Have been playing with the look and layout of my blog and I remembered that changing the sizes of the photos had been easy but no longer. Could only select small, medium, large and xlarge, (bit like dress sizes really) and the graphic designer side of me screamed no no no I want to decide the sizes of my pictures, so what had changed.
Blogger have two Post Editors, an old one and a new one. The new one has the preset image sizes.
So when you have finished writing your post and have added the images, go to your Settings tab, scroll down to Global Settings and select Old Editor.
Go back to your post.
To resize your images, click on the photo and a box with white corner squares will appear. Grab the white corner square and pull the picture up to what ever size your heart desires
(Don't forget to change back to the New Post Editor to take advantages of all the features)