Okay. I didn't feel like you guys enjoyed my first attempt at this tutorial. I mean, I want you to weep with joy at having finally found a way to make your pictures the same width in your (blogger) blog. So, in a much more concise fashion, here's how you do it:
Step 1. Insert your picture.
Step 2. Click on the picture, select "Original Size"
Step 3. Select "Edit HTML". Find the phrase <img and add the following code: width="465"
(Use whatever pixel width you want all your images to be, this might take some trial and error).