OK this is really noob but I need some help. Ive never bothered with at home printing before and its probably about time I got to it.

I have an imac with Aperture and the GIMP for editing, connected to a pretty basic Canon ip1800 inkjet printer. I finally got around to replacing the empty ink cartridges ( laziness I know ) and was playing with some cheap kodak photo paper printing a couple of pictures.

I really dont know how to set up my images sizes for printing. Whats the best way to resize for 6x4 prints ?? I had a play and was getting all sorts of partial images being printed out, so obviously my settings and/or sizing is way out. The print quality wasnt too bad though for a cheap printer from what I could make out !!

These wil only be for me at home for frames and albums and so on so Im just looking for a way to get the best quality out of the gear that ive got.

Please dont go suggesting buying new sooper dooper photo printers as Im not doing anything commercial or for paying customers. I just wanna get it up and running with what Ive got.