Olly, I personally am fine with you posting them here, I would love it, just cite (or links to) what places they came from as best you can (good effort) and go on. If there are any that you know are purchased or copyrighted or the author has asked users to not post elsewhere, don't
Otherwise, have at it... have fun.
Draw a good one of Penguin in a tirade, and that might be a real hit!
It's all good!