I use Instant Ocean. It's nicely priced and an excellent product, used by the majority of hobbyists.
It's best to wait 2 weeks before getting the clean-up crew. Even with cured live rock there will be some die-off, especially in a new tank. However, I got mine in a week and a half cause I got impatient. About 5-6 reef hermits and 2 astrea snails are a good place to start. Also cerith, nassarius, and margarita snails are good and stay small. Avoid the turbo snails as they get big and can knock things over, esp. in a nano.
I'd avoid shrimp or starfish until the tank has been up for at least a month. These guys like more stable water conditions.
As for fish, wait another 2 weeks after introducing the inverts. Once again I jumped the gun at about a week and a half. So you can push it a little, but within reason. Get only one fish first.