Weight Training?

Hello everyone, I was wondering what sort of weight training (if any) everyone does in addition to swim workouts? I tried doing a search but didn't come up with a whole lot. I recently started a weight training regimen about 3-4 weeks ago, and do a different muscle group monday, tuesday, thursday and friday. I've been doing bench press and I'm apparently a total wimp.. This is the one muscle group that keeps getting sore. all the others feel like they're being worked, but don't hinder swimming at all. I am doing weights till the muscles get tired, but Bench press and flys cause them to be a little sore for a couple of days afterwards. This makes my swim workouts very uhhh.... interesting. It's not terrible, but it takes some time to work out the soreness, and my endurance suffers a bit. My question is, is this ok? Should I not be swimming on the days I'm sore, or does it not matter? Does anyone else experience this? ps.. this is the first time really that I've gone to the gym and lifted. I've always done sports, but not lifted weights until now. Perhaps this is an initial hump I need to get over?