There are a couple ways to do this. A lot of CFers use it as a progression to their 1RM. Others do sets across (one weight from beginning to end). I like to hit my 1RM by the third set so I can get 4-5 work sets with a true 1RM.
When doing max singles, you should rest as much as necessary to give max effort on the next set. Some folks just need two minutes. Most here use two to four. I go three to five.