raw

I have the Pentax K100 and with it the Raw file conversion software, I have in the past converted to Tiff and worked on the photo's in Photoshop, but was wondering if I would be better doing all the work in raw and print from there as well.

Not quite as simple as that. For photoshop you are asked to covert using Adobe Camera RAW (or whatever precisely it is called) into a photoshop file when you try and open it. If you are using Lightroom it feels as though you are editing the RAW file directly although in fact you are not changing the original file at all but creating a sidecar file with all your editing commands stored in it.

K.