When dragging jpegs to my timeline they appear but are an enormous size. I assume it is because the pictures are too large therefore could you advise me what is the ideal size I need to reduce them to so that they appear normal in the video. I don't have any decent photo programs and tend to use basic programs like Microsoft's photo editor which came with Office 97 - would this do the job. Many thanks, Learner

Standard definition video (depending on where in the world you are PAL or NTSC) varies.
NTSC is basically 720 x 480, I suggest resizing your images to 1000 x 750 or close. Oversize images just take longer to render and use up precious CPU power. The oversize images really can slow things down especially if you get over 30 or so of them in a single sequence. Resizing your still images just makes sense all the way around.

I also highly recommend spending a few $$ on Photoshop Elements, it will get you a long way down the photo editing road. Even Picasa (free) might be an improvement over what you currently have. There are other free tools just for resizing photos, there are some suggestions here
http://muvipix.com/phpBB3/viewtopic.php?p=16599#p16599

Many thanks for that information Chuck Angel. It's a great help. It is for PAL. I will look into Photoshop Elements etc. Thanks again

For PAL, I would crop the main interest of the jpegs down to 720x576 if it's 4:3 and 1024x576 if you are doing 16:9