Upgrading to Leopard, Help with burning back up discs and Installing Options.



I need help with a couple of things and please excuse my inexperience, still a 'mac/computer intern", I am upgrading from Os X 10.3.9 to Leopard on a Powerbook G4, I have issues with the following:

1). I don't have an external hard drive, therefore I am backing up docs on discs. I can't seem to get DVD-Rs to work as they keep being spat out within 15 seconds of insertion. Can my machine use DVD-Rs, Do I need DVD +, How can I find out on my system which to use. (Just to let you know, CD-Rs work perfectly I just don't have any and had gone out to buy stacks of DVD-R for this process, and my laptop does play DVD films)

2). When Installing leopard, I am prompted to choose from the following and don't have a clue what is best.
A). Upgrade MAc OS X from an earlier version. Upgrade is not intended to remove previously installed applications or files.
B). Archive and Install with a further option to select 'Preserve users and network setting'.
C). Erase and Install with a choice to format disks as Extended(journaled) and extended(case sensitive journaled)

Further info: It says I need 9GB of free space for this and I have only 5.7 GB available. My Itunes plays, but has a library of over 2000 songs that it says it cannot find original file everytime I select a song and requires that I look for it myself, which leads nowhere, so I'm hoping that by upgrading I will have a fully functional music library. I want to ideally keep my documents, my pictures in Iview max and Iphoto, but have been trying to burn them incase I need to erase all.

I would be grateful for any advice anyone can give me re this. Thanks