OK, today I splashed out on a simple bar and some plates. When doing the shoulder press though, my face gets in the way of the bar, so I have to lean my head back slightly. Is there a more form-correct way of doings this?

So far I've done the following exercises with the bar:
upright row, 7 x 88lbs
shoulder press, 5 x 66lbs
bicep curl, 1 x 88lbs

I'm currently trying to lose weight, and so won't be gaining much muscle, so should I focus on more low-rep work, or a high-rep body-building type routine? Which methods would bring the best results?