I've played a lot of Warmachine/Hordes - it's been my main game for the last 4 years or so. The factions are very very well balanced and the rules clearly written; it's an ideal tournament style game. You can also play casually too, of course. It's a lot of fun.
While the basic rules are pretty easy to learn, player skill matters a lot, since it helps you win to have a working knowledge of both your own and your opponent's sneaky tricks.
Re: your question about point costs: PC on the bottom of each card is Point Cost. Warcasters are free, but each warcaster has a +number (usually around +5 or +6) in warjack points, which adds to the army's total, but must be taken in warjacks. So for a 25pt game where you're using a +6 warcaster, you can actually take 31 points of models, as long as at least 6 points are in warjacks.
FA as written on the cards is Field Allowance: the maximum number of that model you can field, which might be 2 or 3 or unlimited or character (unique).
A good place to learn what your models do is Battlecollege (http://battlecollege.wikispaces.com/