Yep. You can copy it from your computer to your phone thru the wire. Or you can download ROMs straight to your phone "over the air"...I would recommend using wifi since ROMs are 200MB+. Either way, boot your phone into recovery and then select "install zip from SD Card" and then select "choose zip from SD card" and then a list should show up with all kinds of folders. Depending on how you put it on there is where it will show up. If you downloaded it over the air it will be in the "download\" folder. Select it and install it. ANd just an FYI, assuming you use clockworkmod recovery, all of your backups will be in the "clockworkmod" folder.....in case you get into trouble....it will not be in the "backups" folder as I think that is a folder related to Titanium backup or something....again...FYI as you go forward with rooting.