Thanks for your interest in Google Boost for local businesses. Google Boost is currently available in the US to businesses with select categories.
If you don't see the sign-up link in your account, it is likely because your category is not yet eligible. Please fill out this form to be notified when Boost is available for your business.
You can read more about Boost in our Help Center: http://www.google.com/support/places/bin/answer.py?hl=en&answer=1040967