Sorry if this is a dumb question, but I just cant figure it out!
I recently bought a Seagate 320 gb external hard drive and wanted to boot osx from it. I want to leave my laptops hdd alone. My hp laptop supports it, but I have no idea where to start at (other than double checking the specs).
I have been googling for quite awhile now and have come across so many methods.

Thanks in advance, and sorry for the noobness, lol.

So you want to boot from an external drive?
Change the BIOS boot order so the USB device option is listed first.