I was just wondering if someone could give me a good workout for a beginner. I took swimming in college and am now a smoker. I am trying to quit. Just looking for a good beginning routine.

Good job with trying to quit smoking... that in itself will improve your output with swimming. How you start will be very individual depending on your current condition.
Are you wanting to do this on your own or are you joining a gym or the Y? Some locations will have classes and such you could look into. Some Y's even have swim teams you might want to join at some point if you like competing.

If you are just thinking of laps you could use a kickboard at first and work your way up. A few laps with the kickboard, a couple laps freestyle, a couple breaststroke, etc.. Some people like to do sprints... slow and easy for a lap, pushing yourself a bit for the next lap, and so on.

You'll have to see how it goes for you... often, if you have been out of it for awhile, you may be surprised how difficult it is at first! It doesn't take much to get out of shape unfortunately.

Take it easy and work your way up. If you try to go all out too quickly, you will end up sore and frustrated which will only increase the likelihood of stopping altogether. If you can entice a friend or family member to join you that can sometimes be a good motivator as well to keep you going.