Lifting is no good, and biceps are not a player in punching, if anything obliques, legs and lower back and shoulder are what you want. I fought golden gloves a few years ago, and im starting to train again and they tell me to stop lifting because it makes you tight, and less flexible. like the post above says push ups pull ups dips. if you want to lift i would recommend resistance training. the biggest thing of all those especially when first starting out is get your cardio up and work on form. power will come with form. and some people are just natural punchers.
hope this helped. and good luck with the training man. if you have any questions drop me an IM: christo2455