is it bad to arch your back when bench pressing also what are some good websites for workout routines?

It is if you find yourself feeling the major tension and stress of the press in your lower back, but I’ve found that arching the back just a bit forces your upper chest to really take the brunt of the stress which is what you ideally want.

As for good workout routines, it really depends on what your ultimate goal is. Mine was to build muscle to a point where I looked like a wrestler, so for me, http://www.bigbeyondbelief.com got me to that goal.