Well you dont need the link from photobucket. There is a code after you upload it there and you just paste it. The pic needs to be 500X500 max to do it the other way. just go to the bottom where manage attachments is.
When you upload them to photobucket from your computer you can choose to size them as you do it. On photobucket under where you hit browse there is a choice option of size. make sure you either choose message board or email size(Both sizes work here).Then click upload. After it is done uploading to photobucket there are 3 codes under your pic in your album. just copy the "img" one and paste it.