Psr777
The registration form says it should be from a website that is accessible 24/7 but how do you get what picture/drawing you want on a website, apart from creating one yourself?
First, to paraphrase Mrs Beeton, get your graphic. Make sure it's the right size for Prune (60x60 pixels), whether it be picture, drawing or whatever. Then you'll need to upload it to a webserver that is "always" available. As PaperTiger suggests, your ISP usually provided a few MB of webspace, and since they
should be online 24x7, that will fulfill the PPRuNE criateria. Your ISP will provide instruction on howto upload your file into your "webspace" (these will vary from ISP to ISP), and what the format of the resulting URL is. The URL is the "address" that you type into a web browser to display your page, and which you will have to type in on the Prune form when buying your title (so make sure it's all working first

)
Hope this helps,
RTFM