In reply to:
I'm interested in adding Wordpress blogs to some of my sites, which would include a seperate blog for different subdomains.
BY doing it that way (with individual subdomains for each install), you will be avoiding most of the potential problems associated with running "multiple" blogs - that's a "good decision" IMHO. 
In reply to:
Since I've never used Wordpress before, let alone installed it in anything, can someone provide me with some direction what I should read and what problems to look out for?
I think you will find that WordPress is going to be one of the most painless things you will have do deal with in web hosting. Here are my "pro tips":
1) As for what to read, the WordPress Codex is an absolutely excellent manual/documentation/resource, and any and everything you are likely to need to know (and a lot of stuff you will probably never need!) is in there.
2) Use the DreamHost "one-click" installer to make your life easier while you are learning your way around WordPress. This greatly simplifies installation, and keeping current with updates.
3) When in the "one-click" installer, choose carefully if you want the "easy" or the "advanced" WordPress "one-click" installation. If you want to have *complete* control over your installed WordPress(es), go with the "Advanced" (dobn't let that spook you - it's only a couple of more steps than the "easy", and it does not require any advanced knowledge). The "easy" install is even easier, but you will not be able to add your own plug-ins or themes (templates), and this could be frustrating to you later (there *are* many themes already included from which you can choose, but you are limited to using those and the plug-ins that DreamHost has made available with the "easy" installation.
4) There are *many* excellent WordPress related "tips and tricks" sites, and tutorials, available on the web ... don't be hesitant to check them out (Googling for WordPress tutorial or WordPress tips will produce more than you are likely to want to read). 
--rlparker