Don't ask me why TypePad doesn't have a search functionality built-in. However, in lieu of that obvious design flaw (I know, I'm being overly harsh.), there is an easy-to-use search engine that can index TypePad files and give good, relevant returns. It's called Picosearch.

I've just started using it, and even though the returns page has some advertising on it and is not completely customizable to mimic the look of my blogsite, I can live with that. If it makes your job of finding information easier, that's all that matters to me.