Hey there fortune,
As austin alluded to, Wordpress.org has a pretty complete set of docs. So, once you've got Apache, PHP (see: Slicehost Articles: Ubuntu Intrepid - installing Apache and PHP5) and MySQL (see: Slicehost Articles: Ubuntu Intrepid - Installing MySQL (with Rails and PHP options)) installed on your slice, I'd start here: Installing WordPress « WordPress Codex.
If you're in a "tl;dr" mood, I'd recommend their "Famous 5-Minute Install".
Later on, you can install an email server on your slice, if you'd like: Mail server setup and configuration.
It can be a little tricky at first, but generally speaking, you can find stuff covering most of what you want to do by searching our articles site, the WordPress docs, this forum and Google.
Personally, though, I consider the hardest part to be the bit where you have to write an interesting blog :-)