I have a 8 port LinkSYS router right now and It's getting to full. I'm going to buy a switch and put my gaming computer and my server in my room. But I need to buy a switch. Will the computers behind the switch still be like 192.168.1.x. Will doing this cause me to have to port forward to my router or something of the sort?
The switch will make no difference. You will still have the same IP addresses, and you will only need to use port forwarding if you had to before the switch.