You never said what your bankroll is and how many days you'd plan to play -- that would help.

I can tell you, you're liable to go up and down as it's darn near impossible to predict a certain amount per week.

Anyway, here's my advice -- probably counter to many others here.

Pick one track or circuit to focus on and stick to that track or tracks.

Keep good notes, use Brisnet's Virtual Stable thing where you can make notes and they remind you when your horses are working or running.

I'm also a believer in video replays, so check out the sites like racereplays where they have most tracks on file.

Make sheets part of the equation, but you can't make them all of it, as evidenced by the thorograph analysis provided here in the redboard room -- they just look at sheets (and nothing else) for plays every day and you'll go broke real fast doing that as evidenced by their picks. You've got to know the horses and have your own opinions and stick to them -- use everything else T-Graphs, etc as added information that helps you clarify and sharpen your opinion.

I think you might also focus on one kind of race like grass races or maiden races -- maiden races are especially good in my opinion -- you can really separate the wheat from the chaff in those types of races when you have an opinion. You should check out some videos on confirmation and stuff and get a better idea of what you're looking for if you don't know.

Certain tracks have clocker services available, that can be worth checking out as well.

Good luck.