There are several aspects of Full Tilt's Poker Academy.
First: Lessons and Sessions. You cannot get any points for these. They are instructional -- but sometimes really good. I think I've watched nearly all the videos and have certainly learned a ton.
2) Sit N Learns: These are quizzes connected to some of the lessons. There are only a finite number of these. It's very important to pay close attention to the related lesson, because you want to do well in the SNL. If you are in the top percentage, you will qualify for the monthly freeroll. Here's the rub -- you can only qualify once for the freeroll. So if you take a batch of SNls -- one freeroll. And you can't take the SNL again for freeroll credit. Once only. So spread these out.
3) Challenges. You need money to complete the challenges, as all are played at real money tables, whether ring, SNGs or MTTs. Each challenge can be completed 10 times, so if you find one that is easy for you, do it all those times to earn the points. You can trade in the points for step tickets or tourney tickets -- I suggest steps. Or other stuff, of course. Then you use the step tickets to move up the steps. A step 3 ticket can be used for any $24+2 tourney. And that can be really nice.
Pokerstars also has a Poker School. (Register through the PS client.) Once you complete the Core test, you can play in the skill game freerolls. These have minimal money attached, but if you can cash in a lot, you might qualify for extra league money. If you get your rating over 1525 after at least 5 skill games (everyone starts at 1500, and each cash raises it, while each non-cash lowers it), you can qualify for a PSO Daily Qualifier freeroll, with entries to the Sunday PSO as prizes. That Sunday game awards tickets to the Sunday Million tourney.