Does multiple sub domain names really bring in more unique users and what are some tips on what words i should use in my sub domains.
More subdomains linking back to your main domain could cause google to give you better ranking in its search, but we are talking about LOTS of subdomains not one or two or 10. Google could also flag your site and zero it for doing that if their bot catch it as a way to fool their engine.
It doesn’t bring in more users, it is a trick to improve ranking
Fadiz is correct.
It’s just a low-rent ploy to trick Google into thinking that you have a lot of sites linking back to your site (one of the components of the algorithm). I would be surprised that Google would count these, however, as they are really just pointing to themselves. I am thinking that the good people at Google are a little too smart for that.
This will not do anything to help you get on the front page for any search term, and it will not help you get any more traffic.
My only guess as to why google calculates it as a link is because some ISPs allow you to have your own sub domain homepage without having your own full domain name. Their algorithm changes all the time, so who knows what the future will bring 
I have decent experience with SEO (search engine optimization) and the best thing that will help with your SERP (search engine results page) is links to your site. And I’m not talking about those silly link trades cause they are useless. The more inbound links you have the better you are.
Getting your link on a site that has a decent google page rank is worth tons in the SEO business. Download the google toolbar and start noticing sites with page rank. you want your site to have page rank. It doesn’t hurt to pay for links either. Google is all about content. They don’t care about flash or java or any of that fancy stuff. the more ORIGINAL content you have the better.
thats my 2 cents for the day.