front wheel removal

is there any trick when dealing with the brake when you take the wheel off, like do the pads come out? also, do they need to be compressed alot to slide the disk back in? I need a new tire and its alot cheaper if I take the wheel off myself

Look here

Normally you can just slide the disk right back between the pads, if they fall out just stick them back in.
Just don't touch the brake lever while the disk is out