Looking for a strength training program for a beginner

Generally, you'll get more benefit out of putting the time into triathlon specific training rather than train with weights. The exception is if you are over 50 in which case, weight training is beneficial because you are losing muscle mass.
If you do weight training, it's better to do it in your base phase. The best training works the muscles you use in triathlons - squats, planks for the core, tricep lifts, calf lifts. I do them 2 - 3 times a week with light weights, 3 sets of 25 each. (planks 1 min) Try to increase weight or rep number every week or two.