My mother has just set up her own Flickr site (she and my almost 8 year old nephew in Edinburgh have just set up their own blog too) and I've just been helping her get out of a little pickle.
If you intend to have slideshows on your blog you will need to take care when adding tags to your photos that you use tags that allow only your photos into the slideshow/photostream. For example, Mum and Dad have recently had a holiday to Egypt and Mum put a slideshow on her blog with the tag Egypt. She was then thoroughly miffed and frustrated when photos appeared in her slideshow that she and Dad had never taken!
When I tag my photos I use "Springwood Colquhouns" as one tag on everything then add "Springwood Colquhouns XXX" for a specific event/set of photos so they can be shown on one big slideshow or on topic-specific ones. Photos may end up with half a dozen tags. I find using an Excel spreadsheet helps me remember what I've used before.