"too big to upload" is the file size, not the size of the picture.

For example, the picture size of this one is:

200x150 pixels (3% of one megapixel)



This one is:
100 x 75 pixels (0.0075 megapixels)



You need to start with a bigger picture, and do two things:

1. reduce pixel size (width x height)
480x320 is good for this site and is the size I normally use. I don't go bigger than 640x480 because it's too big for an 800x600 monitor when put into the web page. I normally don't go smaller than 320x240.

2. reduce file size
Use JPG format (like you did). But you can adjust the "quality" when saving it. Your graphics program may have a "quality" setting when saving it (or 'advanced' settings). I normally use 76% quality (medium) which looks great.

What photo software are you using to resize the pictures? We can give more specific tips.