Progression of an on-line player?

Hey gents,
I dont like to think I am a beginner as have been playing regularly for just under a year and have progressed reasonably well. However I am certainly neither an expert, nor a particularly advanced player either and I need to improve.
I like to use online poker to make a bit of money.
I only really play no-limit hold'em tournaments and usually play this at single tables small stakes.
However my win rate at the moment is pretty good on these tables($5 or $10).
If i want to progress as a player (and hopefully as an earner), how should i go about it?
Should I go upto bigger stakes single table tournaments?
should I start playing more multi-table tournaments? (probably fairly conservative at first)
Also is playing conservatively in no-limit ring games a good choice?
Also beyond gaining experience at the tables I enjoy reading books such as harrington on holdem to try and advance my game.
Any advice or pointing me to some good threads on how to progress in on-line poker would be greatly appreciated.
Is there a natural p[rogression of what kind of tables you should go on to advance your game?