Can anyone help me? I was just wondering whether there is only a certain brand of disc that is compatible with my mac dvd-r drive, or will all blank discs work?

I don't know, but hang on, somebody will probably answer.

What does it say in Help?

I think the important thing is buy DVD-R discs and not DVD+R.
Also, if you want to use 4x discs you will need to update the firmware for your machine if you have a Quicksilver G4.

Info below is from the Apple website.

All SuperDrive-equipped Macs are compatible with all currently shipping 1x and 2x DVD-R media; this update relates only to the new high-speed media that will be available later this year.

Important information about using high-speed media with your SuperDrive-equipped Power Mac G4 or iMac.
Apple is the industry leader in providing affordable and easy-to-use DVD authoring systems. Although all SuperDrive equipped Macs are compatible with all currently shipping 1x and 2x DVD-R media, new higher speed media will become available later this year — it is important that your SuperDrive be up to date before using this new media.
Using new high-speed media.
The DVD Forum recently released specifications for new high-speed discs for DVD recording (4x for DVD-R and 2x for DVD-RW). Media based on this new specification is expected to be available later this year. All SuperDrive equipped Macs can easily be updated to be compatible with this new media. Apple is providing a quick and easy way for customers to update their SuperDrive before this new media becomes widely available. This update will be available as an automatic update and as a manual update for both Mac OS 9 and Mac OS X.

formatj's correct; Apple sells its own brand, and they are DVD-R, not DVD+R. (CompUSA carries them, so if there is one near you, you can inspect an Apple DVD-R box and compare the specs. There are DVD-R brands that are cheaper.) Also, just to be thorough, you want to specify general-media 4.7 gig disks--not "authoring" DVD-R disks. Here's a link to a .pdf file that explains the difference:

http://www.pioneeraus.com.au/multimedia/dv...oring_media.pdf

In the blurb that formatj quoted from the Apple site about updating the firmware of the SuperDrives before using the "new high-speed media," what *isn't* said is fascinating: fact is, putting the "new higher-speed media" (>2x) in a non-updated drive can cause the laser to turn on and stay on until pungent ugly smoke starts pouring out of all cracks and crevices as a result of SuperDrive meltdown.

Not a joke, really: this is literally what happens, so it isn't a warning from Apple to take lightly.