I don't know if i can post links, so i will only say some basic things that i know.
You should allways keep a certain amount of buy ins to a limit. Like, if you play in a 0,5/0,10 NL you need like 50$ to play in that limit, and you only enter with a certain amount of big blinds. It depends on the strategy that you use, the minimium buy in is 20 big blinds, so having 25 buy ins of a limit is a good way to not lose too much when something goes wrong.
If you start with 20 big blinds, and after winning a big pot, you are like 35, 40 big blinds or more, you should leave the talbe, and enter again on it with 20/25 big blinds.
Allways enter in tables with 7 opponents or more, so you wouldn't pay the big blind so ofter.
I hope this helps, this is some basic stuff that i can remember.