1st and foremost you should do whatever you're happy with. If you are comfortable where you are do not feel like you have to change for others. However if you do want to change, I suggest getting into pumping iron. Push ups and sit ups are a good warm up but if you really want muscle hit the iron. Good luck man.
yeah i like bigger guys...i get creeped out when theyre skinnier than me...you need to lift tho man if you want size...but ya kno everyone has diff taste