all members have a limit to how many pictures they can upload. once you hit that limit, you have a couple different options.
1) go into your user cp, and under the manage attachments tab you can go in and delete old pictures to clear up some space.
2) if you are not already, you can sign up to be a supporting member, that have an increased about of avalible upload space(I want to say 10x as much), that can be done here: Upgrade your WF account here
3) join a photo hosting site and link your pictures here. there are lots of different sites like photobucket and imageshack. we also have a how to section detailing this located here: How To Post A Picture