It is pretty easy. you pick your roster and have 4 subs (1 keeper and 3 position guys). It auto subs for you if a guy doesn't play. You can make one free transfer per work and any additional ones cost you 4 points per move. Also have one free "wildcard" where you can make as many transfers as you want with no reduction in points. It isn't a head to head thing, instead you accumulate points over the season and most points wins the season. They also have a random head to head competition similar to the FA Cup with the winner of that winning prizes (there are like 100,000 people in the knockout competition).
It is sort of like FFL where you only have to set your roster once/week and it is good for that weekend's games. If you fail to make changes, your roster and starters just roll over from the previous week. Select a captain and his points double for you.