First, Read this great post
ArtVandelay's general advice on big bet hold'em
After reading that, the first thing you will be thinking is "geez, that's not how I play SNGs at all"
Well, yeah, that's what I was thinking too. SNGs do not play a lot like actual NL ring games. In SNGs you will find yourself going all-in pretty often, especially as the blinds increase. In NL ring play, you can't do this as much without a really good hand.
To make the transition less painful, I'd start out on a site like party where the stacks are not as deep. This actually does play a bit more like SNGs and the players are abysmal. I would bet that you could make money on the party $25NL just playing pocket pairs and AK and limping with every hand except AA,KK, and AK. I'm serious.
Hope that link helps
Brad S