Canon FL/FD mount lenses are not good choices for adapting to Canon EF-mount bodies (e.g. 30D, and any other EOS camera).
There are FD-EF adapters on eBay, but to be able to focus to infinity, you would need adapter with corrective optics because of negative difference in focal flange depth between these two mounts. Unfortunately, corrective optics degrade picture quality significantly, even when using original Canon FD-EF adapter (expensive and very difficult to find). With adapters without corrective optics, lenses cannot be focused to infinity.
Specifically, with lens this long, you could focus close to infinity even with non-corrected adapter (without lens element), so if you can score one adapter for cheap, it's possibly worth the hassle.
Basically, avoid FL/FD lenses if you're using Canon EOS camera - they are not a good match.
If you already have one, get an adapter off the eBay - adapters without glass are macro-only, adapters with glass degrade picture quality.