Can someone tell me how to burn an ISO onto a blank disk on linux! Thank you !

Take a look at:
http://linuxiso.org/viewdoc.php/howtoburn.html

If you can let me know what software you're using to burn I can be more specific.

Here's instructions for GToaster (the only ones I can remember off the top of my head).

Start up GToaster and in the upper 'local' filesystem window locate your iso. Then drag it down to the 'CD' filesystem box below, make sure you drag it to the 'Tracks' listing though (the second tab) so that toaster doesn't copy the actual file but instead writes the ISO's contents to disk. After the ISO is listed in the second tab (the Track tab remember) go ahead and burn. You should be good to go.

I don't remember XCDRoast in as much detail but I do know that you'll want to place the ISO into your 'images' directory as it is configured in XCDRoast. Once the ISO is in the appropriate directory startup XCDRoast and click the appropriate button (I think it's Master Tracks). The ISO should be listed in the far right listing. Drag it over to the first listing and then click (I think) Write Tracks.

That should do it, but don't quote me on it. Again this is off the top of my head and whatever software you're using should have a FAQ specifically for burning an ISO.

i just use cdrecord

man cdrecord to tell you what to do first to detect your cdrw to tell you what dev= it is, but on my laptop this is the command i use:

cdrecord dev=0,0,0 speed=2 filename

reason i limit mine to 2x speed is i have a crappy cdrw and use low end media. if i burn an ISO any faster it fails on the install. now for music i can let it burn at 8x. that is as fast as my cdrw goes.

when i keep my speed=2 i have yet to have a bad burn even on cheep media.