I suggest using to search function to see the many other threads on the same subject.
As for advice, here's a COTW I wrote several years ago.
http://forumserver.twoplustwo.com/78...g-down-729719/
It has been 4 years, but all I'd add is that at higher levels, you'll see far fewer super weak players. There will be fewer open limps and more raises pf. At 2/5, you'll start to run into people who are trying to make a living at poker. None of that means they are good. But they aren't stupid terrible.