The first thing you have to understand about Empire is they're human. This means they're not an army of massive beasts or fast Elves or cheap and expendable rats. They're average. Their strengths are in numbers, flexibility and synergy. It's an army with lots of tools to get the job done, but each piece is only as strong as the one next to it. It's a fun and flexible force that I can't wait to field myself.
Lords
General of the Empire- He's your basic commander and a good choice to lead your forces. He brings LD 9 which is great and has a bunch of options to customize him. Remember, though he's just a human so he's not a beastly combat unit. He can be built for what you need, though and has tons of choices. He also gets the new "Hold the Line" rule. The unit he's in takes panic tests with 3 dice, only counting the lowest. It's like cold-blooded light and makes your units pretty resistant to being run down when they lose combat.Templar Grand Master-He's a bit more fighty then the General, but he's still only human. He comes with fulkl plate on a barded warhorse because he's designed to lead knights into the fray. This is another decent leader for your army, though in larger point games you may want to take him with a bus of knights for some punch, but keep the GotE as your General for his leadership in your main force. He can add to his ability with 100 points of magic items and he makes your knights immune to psychology. If you take knights (and as we'll see later they're awesome so why won't you?) he's a great choice to add to your army.
Arch Lector-He's an interesting one. He's at best a mediocre fighter, but he's the first real synergy entry in the army. First, he gives the unit he's in Hatred, which alone is pretty sweet but beyond that he brings prayers. Now I'm torn on these because of the nature of bound spells. They're useful and can bring flaming attacks, boosts or a ward save, but they use power dice which are something of a premium in 8th edition. The good thing is you can toss one die at it and if you roll a 1 or 2, there's no broken concentration because it's a bound spell. They lost the automatic dispel dice, but they can channel both power and dispel dice, so that's nice. He also has the option of a War Altar as a mount. Now in the last book, this thing was awesome but this time... Well, it extends the hatred to a bubble around the Lector and being a large mount will extend his LD bubble as well if he's the general. The bad thing is the ward save no longer extends to the Lector so he needs to invest in his own. It got more expensive too so it's just not as good as it was for more points. What really annoys me is they made it not worth taking, but released a beautiful model that was lacking last edition when this was almost a 1+ for most Empire players. The Arch Lector is a decent choice, but the other lords will probably suit you better.
Wizard Lord- He's a human that knows magic...and that's about it really. The cool thing is Empire is one of the few armies that can take all 8 lores so you can do anything with him. If he goes Beast which is a decent choice for Empire, he can take a Griffin mount. There are other new mounts, too but I'll cover them later because they can also be taken on their own. Personally I'd take Life or Shadow on this guy.
Heroes
Captain-He's a lower ranking officer and basically plays like a junipr form of the General. He also has Hold the Line and can take 50 points of magic items. He's a good cheap command model for small point games and most importantly, he's your BSB. Remember he's still just a human so don't expect him to fight toe-to-toe with some of your nastier baddies but he's cheap and good at what he does.
Engineer-He got nerfed. Plain and simple. He used to be a great warmachine babysitter because he could re-roll a misfire on any one warmachine near him. Now he has to pick one before they fire and can only help that one. He can lend his BS to a volley gun which isn't a bad idea but still I don't think he's worth the points anymore.
Battle Wizard-Pretty much the same as his big brother Lord, but he can only go to lvl 2 and doesn't get the big mounts. He can also take all 8 lores which adds to your flexibility. I take Beast here or sometimes Fire if I feel I need more ranged punch.
Warrior priest-Take the Arch Lector, shave off a wound and the option of a War Altar. Take his magic item limit down to 50 points and here's the Warrior Priest. Again good for the Hatred and the channel attempts and cheap enough to bring a few. Not the most capable fighter but it's the bonuses he brings that you're really investing in.
Witch Hunter-Here's one that can be fun, but only if you have the spare points. Again, he's cheap (this is a theme in the army mostly) but you can'ty give him any upgrades so he's fragile. He does have some cool tricks though. He picks a "Heretic" at the beginning of the game from the enemy's characters and it becaoes his mission to kill that character. He has a pistol that he can use against his target with the Sniper rule, but here's the cool thing..all his attacks have Killing Blow against the heretic. That includes the pistol. He has little in the way of protection and will quickly die to even a mediocre combat character so bear that in mind before tossing him into a challenge with his heretic, but he also has Magic Resistance that he grants to the unit he's in. As I said, he's OK if you have the points but I wouldn't go out of my way to get him in.
Core
Now before I start with Core, I have to talk about detachments. Most of your Core can be taken as parent units or detachments and things have channged. First, it's no longer pointless points as they do count against your Core if their parent unit is Core. Greatswords can take detachments, too but then their points are in your Special budget instead. The detachment cannot take command and deploys with the parent unit. As long as they're within 3 inches of the parent they share certain special rules if the parent has them. They can also react to charges to the parent, though if they counter charge, it's done as a normal charge now. Honestly I still don't use them but they got much better now at least. Unlike many of the newer armies, core prices went up a point or two pretty much across the board, but the argument could be made they were a bit undercosted before. Most of your core has pretty much the same stat line and everyone but your shooters have light armor, so it's basically what they carry that changes. I'm not going to say what's better because that's an unending debate that's been going for a while. I'll just cover how each lends to certain play styles and let you make your own decision. This should be quick.
Spearmen-Humans with spears. They can take shields. If you weant to play defensive and want as many attacks as possible, here's your choice.
Halberdiers-Humans with halberds. They can take shields. If you want to make the most of your attacks with a stronger punch, here you go.
Swordsmen-Humans with Hand weapon and shields. These guys also are WS4 and since they get the parry, I feel they're the most well-rounded choice. They make good detachment choices, but I run a horde personally in my core.
Militia-I know I said I'd avoid the best or worst, but here I'll make an exception. These guys suck. They have 2 hand weapons so 2 attacks, but they're naked, and not as cheap as naked humans should be. Pass on them.
Archers-Human skirmishers with short bows. Again, they're naked. If I take them, I'd pay for the upgrade to Huntsmen so they can Scout. Of course this also makes them Special. Don't expect much since they're only BS3, but they can be a nusiance that your opponent will have to decide to do something about or ignore and have arrows raining from their backfield the whole game.
Crossbowmen-Naked men with Crossbows. Again BS shooting but with a decent range. Move-or-fire so this is a good thing.
Handgunners-Naked men with rifles. More BS shooting, but now they're armor piercing. This is a fun choice because the champion can take one of the special guns. The Long rifle is fun because you can try to pick off specific models. It's not easy, but when it does work, it's pretty cool.
Knights-Now we're talking. Empire Knights are great. They're fairly cheap and well armored. This time, there are 3 flavors. You start with the basic Knights which come with a lance, a 1+ armor save and are cheap. If you take these, I'd upgrade to great weapons. You do lose a point of armor save, but they're base strength 3 and let's not forget the days of the devestating cavalry charge decimating a unit are gone. You have to plan for the long fight. for a few points more, you can make one unit Inner Circle knights and are now base strength 4. Here I keep the lance for the 1+. There's a third level knight but they're Special and we'll cover them and the Rare's in part 2.