B&M Question

Ive not played a lot of poker in card rooms. What I have has always been limit. So ive been really getting into NL lately. My problem... I dont know the ettiquites of NL tables. Namely - how much do can/should I sit with? Should I prebuy my checks? I know in limit, especially lower limits, they prefer you get your racks from the cage. Does this apply to NL tables?

thanks for the newbie advice.