This is no beg. guide, but I'll throw out a few pointers that helped me...

Find Downunder Stables post about winning money on the Gold Cup, it helps a ton.

Look for horses that can run 5 (preferably) or 7 furlongs early, those races are rather prominent and you can earn money as best as possible.

"By Group 1 Winner" is key.

I enjoy racing and selling too...but often. Computer will pay good money for a horse once he's run a good race. If you know he's not that good, and most likely won't run that well again, sell it.

I don't race at 2 usually, seems to be more of a money burner.

Don't be afraid to wager... you can really cash in.

When you get funds, I just buy the top horses w/reserve in the sale, and send off the ones that stink almost immediately. Sometimes five years from then the horse beats me in a grade one, but more often than not, they suck more.