If you want to make your own, here are a feeeew tips:
1) You're going to want your pictures to be large and clear. So during game play, go to options and make picture size LARGE and BEST quality.
2) You can find your pictures stored in your computer in one of the two ways (depending on what expansion packs you have, or don't have):
My Docs > EA Games > The Sims 2> Storytelling
My Docs > EA Games > The Sims 2 > Neighborhoods > N001 > Storytelling
The pictures will all be shuffled since TS2 likes to give all the pictures names with random numbers. So getting the pictures up in order is, in my opinion, the hardest part.
3) You're more than welcome to post the pictures here in the community, of course, but make sure to use an LJ-cut. Just put the following "code" in the very beginning of the post: <lj-cut>. To start a post here on LJ and this community, click here.
4) If you've never uploaded pictures, I recommend Photobucket. Photobucket will give you a link to put the picture up directly. It will say HTML TAG.
I think that's all. I am in no way a 1337 computer expert, but I'd be happy to help someone who is n00bier than I am.