Every time i hit record weather im using my computer mic or my usb mic i get feed back why?

I'm having much the same problem and can't find any support online. Whenever I click input monitor or record enable. Mine sounds like it's internal (not from an attached mic).

I'm running LE 8.0.2 on lion, MBP

Try using headphones while recording if you are not already doing so. Sound from your speakers can enter the microphone and cause feedback.

It's most likely caused by the placement of your mic device in relation to your speakers/monitors. Try adjusting their relative position to escape the feedback "loop." Or use XLR cables to ensure you're grounded properly.