Getting images – some suggestions:
Use Shrink O’Matic http://toki-woki.net/p/Shrink-O-Matic/
Use Photoshop or anything that makes life easier for you, but only if you are comfortable with it. Searching Google shows that there are lots of online tools: http://www.google.co.uk/search?q=shrink+images+online
You may already use Flickr, with its online storage and it’s uploader; or Google’s Picasa, which also allows you to store images online. Another way to include images in your blog is to link to them, on those services.
Extension reading: There are also widgets that facilitate further functionality, as described here: