get the liveCD. The Install CD is a text-based installer, so you might not understand everything, but the liveCD has a better partitioner (and even lets you browse the web, do work, etc. while you install).
The disadvantage is that the liveCD requires a fair sum of RAM (~256MB recomended), so if you have an old system, you should get the Alternate one.
Just remember to check the md5 checksum (The partitioning tool got messed up on the disk I tried