How to connect your own domain to wordpress blog

1.I'm buying domains in yahoo
2.When your domain is active go to Dashboard -> Upgrades -> Domains in your admin wordpress account, enter domain name in the text box after http:// and click on the button "Add domain to blog" - you get message
Credits
Domain mapping is available for 10 credits per domain per year, registration not included. You have 0.00 credits. You will have to purchase additional credits via PayPal. Note that some forms of payment (eChecks) may take several days to process.

Possible problem with tomorrowstyle.com
We were unable to verify that tomorrowstyle.com is pointing to WordPress.com. If you own this domain, follow the directions below to get it ready for your blog. If you don’t own it, try a different name to see if something else is available. If the domain is available, you may be able to register it with another registrar and then map it to your blog.

How to fix it
Using the DNS tools provided by your domain registrar, remove any existing nameservers and add the following:

NS1.WORDPRESS.COM
NS2.WORDPRESS.COM
NS3.WORDPRESS.COM
Then come back here and try again. It may take several hours for our system to recognize the changes.

4. Go to yahoo small Business, click on the Domain Control Panel that you need
5. Click on Edit Domain Locking
6. Click on the button "Unlock Domain", also in the next screen too
7. Back to Domain Control Panel and click on Manage Advanced DNS Settings
8. Click on Change Nameservers
9. Replace yns1.yahoo.com to NS1.WORDPRESS.COM, yns2.yahoo.com to NS2.WORDPRESS.COM and add in Additional text box NS3.WORDPRESS.COM, click on Submit button
10. Back to wordpress admin account and clikc on Try again button
11. Click on Buy 10 Credits button
12. After paying 10$ from your paypal account you back automaticly to wordpress and choose option - put my blog on own domain