I know the thread is old but a few points to share (if anyone cares). I was a competitive swimmer and have been a swim coach (high school and club level) for almost 30 years. Last summer my son and I took up some training for a tri. He has been a high school swimmer (then for 3 years). (He is also in track and cross country, 2/3rds of the way there.)
He trained ( for 4 weeks) 2 days a week for swimming, 5 for running and only 2-3 for the bike. (He has never been a biker.) He was 7th overall in the swim with very little training (4th in the run and 151st in the bike (on a target special) , 31st overall, he is biking alot more (on an 80's peugeot tri bike)). He just swam some long easy sets 5x200's, 12-15x100's, 4x500's (never swam father than 500 yards at a shot). After seeing the results I've come to the conclusion you can't win a tri by being a good swimmer but it can really hurt. (His was a sprint and the swim was about 400 meters (he was around 6:30 and a few in his age group were over 20 minutes.)
The following are what I would suggest you work on asa beginning swimmer;
1) Become relaxed in the water- this can be a struggle with my new swimmers and can take up to 2 weeks of 3-6 days a week practice. (Usually comes from familiarity with the pool and strokes.)
2) I would suggest swimming mainly freestyle.
3) Don't worry about the kick, long easy freestyle takes all arms and very little kicking.
4) For new comers start by using a pair of fins while swimming.
5) I would suggest swimming 25's and 50's the first week, 25, 50 and 100 the second week, 50's and 100's the third week, and after up to 100's, 200's and more after that. You are better doing more reps than a longer swim (at first). A typical set is 10x50 pulling/swimming freestyle on 1:30 or 2:00 for a beginner on 1;15 for a decent swimmer and 1:00 or faster for a good swimmer.
6) Pulling is also good, it keeps the hips high and lets some people relax abit.
If you need any other hints, let me know.
Good luck!