Thanks for replying kitkat.
Not very complex at all, pretty much just combining imagery and text, mainly for print. The company we use require the files in a certain format (cmyk, bleed etc) which I can't do with most free apps I guess...? The company is print24.
Gimp apparently is decent, and free, but are the files compatible across platforms? For example if I start working on a mac and mover over to Windows?