A few years ago I thought I knew what I was doing, whereas now I KNOW I DO NOT! heh. I scanned a bunch of photos at 2400 ppi and saved them as PSD files. I know now that I should have saved them as TIFF files. In regards to compression, did those files get compressed when saved as PSD files? and if I want to save them over to TIFFs would that be a mistake?

PSD is a superset of TIF. The only possible problem you might run into would be some future app not being able to read PSD files. Both formats are lossless, and converting from one to the other will not lose any data (at least at this point, if you do edits that might not be the case). And at this point, the files are approximately the same size, although TIF might be able to make them a bit smaller if you turn on ZIP or LZW compression during the conversion.

GREAT!! Thanks Doug, I was hoping to be able to convert them over then use the zip compression in TIFF.