"So the winner is basically the rider with the most laps ridden in the alotted time? There is no sprint finish or set lap # ?"
There's a lot of physics involved in racing, and a pack will ALWAYS ride faster than any individual. Beginning 4/5 races will usually average 24-27mph with intermittent sprints up to 40-42mph. The cat-3 races typically have the highest average speed of 28-31mph with sprints up to 42-44mph. The 1-2-Pro races are longer with more team and strategy involved, so they typically have slower average speeds in the 27-31mph range, BUT, there's a tonne more sprints all the time and they can get up to 43-46mph on the flats.
There are intermediate sprints for prizes & points call primes (French, pronounced as "PREEM"). These can be $100 gift-certificates, sunglasses, jerseys, etc. up to $10,000 cash primes in the 1-2-pro races. There are various strategies involved in winning a prime, or taking advantage of them to get off the front.
So you'll find that the very first basic strategy one picks up is how to draft and hide in the pack. First goal is to simply stay with the pack and not get dropped and finish a race. Next comes actually competing for some of the prime sprints. But be careful because you may work a little too hard winning that sprint only to get dropped by the pack and not even finish the race. So you might want to hide in the pack the entire time and contest just the finishing sprint.
That's what I find so fun about crits, it all comes down to strategies for the sprints. The distance and laps are just filler material between the sprints. There's an unlimited number of strategies for winning the sprints, depending upon the course, your personal strengths, the teammates you have availble and what the other players in the race are. Simple strategy is keeping an eye on the top 10 finishers of each prime and tracking them. Then manuveur around the pack to be near these guys, then when they take off for sprint, you just draft off them and nip them at the line. Some of these guys are like football linebackers though and they can get up to 42-43mph all by themselves on the straights. It's hard to accelerate from 43 to 44mph next to them once you pull out in open air. So one strategy to beating strong sprinters is to take off yourself 1-km from the finish and if you can get 30-50m ahead, you might be able to hold them off til the finish. This is not likely though, so you'd need teammates, 2 at least. One guy to lead you out at about 1-km out and one guy to coast around the last couple of corners to slow the pack down just slightly.