Congratulations on your success at the $5 tables.

Your goal now should be to not be tempted to do what you did at the $2/$4 tables ever again, lest you think yourself a poker god and slaughter your bankroll in a week (see also, the Newbie Circle of Death in the beginner's section).

Play well, play within your bankroll (there's a thread on that in the beginner's section as well - short answer is $250 for $25NL is quite risky), and the results will follow. After you've established yourself at the new limits, then you can look at what your returns should be.

Also, bonus whoring is a great way to build a bankroll. Definatly look into it once you have a solid $25NL game.