Has anyone been into the Apple Store regarding an iPhone that won't turn on?

My iPhone won't turn on so I'm going into the Apple Store tomorrow to get it sorted. I wondered what they would do and whether I would lose any data because I have some gorgeous photos of my baby nephew that I really really don't want to lose! Has anybody been for this issue and can tell me what they did please?

My lock button's a bit jammed anyway but I went to reboot my phone earlier due to signal problems and the apple logo showed up but then the phone didn't come back on, despite connecting it to several chargers and trying the lock button alone and the lock and home buttons simultaneously.

If your contract is up then I would just trade it in and get a new one on a new contract, thats better then putting money into fixing an older version and you get money back for it on trade in.