Page Meta Descriptions – Please Help!

Hello everyone! I have a couple of questions! Thanks in advance for your help, its is MUCH appreciated!

I need to change the meta description for each of my pages. For example, I have a page on gaming, and I would like to create a description accordingly for just that page.

Also, am I right when I say that the description meta tag will be used by google as my “snippet” when I get ranked? By that, I mean if my title is Gaming, and my description tag is “the best games around” will I show up in google like:

Gaming
the best games around
http://xxxxxx.com/gaming