you want loose players, both preflop and post flop. The more the merrier. Big pots are also good.

At NL small pairs are playable frome pretty much any postion (be careful with baby pairs in big family pots as your more likely to be set over setted).

Continue to play tight from up front but u can add small pairs.

Try not to go broke in unraised pots or with a one pair hand.

What about aggression? The problem with tables where the pots get TOO big is that it could well mean there is a lot of pre-flop raising and I can't see flops with my speculative hands cheap. Is that something I should worry about?

You mention small pairs. One thing I've always struggled with in NL is what to do with small pairs or suited connectors with a raise in front of me. Should I be willing to call a reasonable raise PF with them if there are (or I have reason to beleive) there will be another caller or two?

Also, should I generally raise with hands like this if I'm the first one into a pot? By rule of thumb, I will almost NEVER limp in limit if I'm the first to enter - it's either fold or raise, but I'm not sure that would apply to NL.