There are plenty of places online where you should buy site names. GoDaddy, DomainCheapsters are 2 of the commonest, and one’s I have personally used. Domain names are cheap typically around $10 a year at the most. I know at DomainCheapsters if you buy six or more at a time they are around $6 to $7 depending on the extension you get.
There’s a lot of opposing opinions about whether you must get any domain with a different extension such as .net or .org for example. Personally, I’ll use a .com, .net or .org. I have revealed that any of them work well for my needs and .net are rather cheap. You’ll have to find what’s best for you, but you need to remember something : many people will say that customers will forget a long URL or a different extension, which is right but how do you target the majority of your customers?
If you aren’t handing out business cards and expecting them to type in the site name than it’s not such a big issue. Most of the traffic I am getting is either from searches or from online marketing and in all cases my website visitors just have to click on a link which is why I think having different extensions has not had a bad effect on my business. bother to establish your Internet presence, don’t get fooled into thinking that going the ‘free’ route with a blog is the simplest way to go.