Free ways to get blog traffic
-Clickthru.com
-Free link directories
-Rss Directories
-Ping, always ping (wordpress will do it, there is a list at wordpress.org of all the ping sites you can hit)
-create a myspace.com page for your blog
-put your link in email and forum signatures (always read forum rules first)

Paid ways to get traffic
-Google Adwords
-Buy advertising on another blog, private sales
-Try Bidvertiser.com - cheap clicks that get traffic
-Paid directories - generally better targeted traffic and higher PR

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The above posts are all good information. Do some research if you can. If you don't have a lot of time, you can follow my list and others here, you will see traffic increase in no time!