P_P, we dont allow uploads (except for Premiere members). You can not control quality during uploading, and as a photography site, quality is the key.
If you have your photos hosted somewhere else, posting them here is easy. just put the URL of the image between these tags:
If you dont, upload it to your gallery, tutorial on gallery upload is in the Knowledge base.
If you dont have enough space there, you can either a: make your images smaller by saving for web, or purchase the yearly subscription to the Premiere Membership, which gives you SO MUCH space, for $10 per year. All the money from those go into upkeep and betterment of APF, so you are helping the site. Neither me nor Jay take any money out of it, so you are not making anyone richer

And, it's one of the best space-per-dollar deals on the web.