Deyvsonflp is absolutely right. These 45-180 man on
pokerstars are mostly for improving and building up your
bankroll. They are also handy, when you dont have 6 hours to play some of the slow MTTs like the "big" or the regular speed PKOs. However if possible I will advice to start with a 100$ deposit or more and focus on the 1$ and 1,5$ events, as Deyvsonflp suggest. The issue with beginning at the 25c limit is, it will take forever to grow the bankroll to a level, where you begin to make some actual money.
Furthermore the 50c are all turbos, and that create a significantly capped ROI and limit the amount of postflop skill building by playing these events. The highest ROI is in those with 15 min blinds, which are the regular speed 90 and 180 mans. The regular speed 45 mans are somewhere in between but still ok, especially when you dont have so much time.
As for strategy all these formats attract quite a few grinders, who are generally beginners. They are playing a tight and aggressive style, and often they are simply to tight. This mean, you can abuse them near the bubble, and often you should overfold to their aggression, since they are rarely
bluffing or 3-betting light. Of course you should also identify and exploit the few recreational players, who find their way. Ideally you want to use a HUD to identify them, so maybe start with a free HUD of some sort. The most important is, that it register VPIP and PFR.
Actually right at this moment I am in the process of rebuilding my bankroll on PokerStars, after I had withdrawn all my winnings and used it for life expenses. I have deposited a bit over 200$ and started with formats like the 1,1-2,2$ MTTs plus a decent amount of 3,5$ SnGs. A bit aggressive with the bankroll in the beginning, as popping some more money in was always an option, and I could also just play on
888 Poker.
After 727 tournaments I currently have a profit of 736$, and now I can very comfortably play 7$ SnGs, I can play MTTs up to 7,5$, and I am also taking a few shots at 11$ MTTs again. This just to say, that it can be done, but if you are starting with just 25$, its going to take an awfull lot of time to get to those 200$, where I began the process this time.