UPDATE.
*******
Ubuntu is now on ver 11.04, it's been a while already, means it's mature enough to install it.
Looks outstanding, feels good, and of course: steady as always.
For dosbox, not much is changed, follow the 10.04 rules and all will go swell.
Maybe some CD game tips:
Don't use your CDs but create an image with the excellent Brasero, ISO or BIN/CUE created with Brasero are fully dosbox compatible.
If you have no idea about the differences between ISO and BIN/CUE always go for BIN/CUE, works always....
Use
imgmount in dosbox.
As usual, if you need more help than this, get your ar*e back on Windows or Mac ......