1. Login to the domain manager at http://register.web.com.ph/customer for .com, .net, .org (For PH Domains, please visit https://clients.web.com.ph/knowledgebase/182/I-want-to-setup-custom-DNS-for-my-PH-domain-ph-comph-how-can-I-manage-that.html)
2. Enable the Managed DNS service. This is free-of-charge.
3. Create four separate A records for your naked domain (ie .yoursite.com) using the IPs 188.8.131.52, 184.108.40.206, 220.127.116.11 and 18.104.22.168.
5. Now log into your blogger account and switch to the settings page. Look under publishing tab and select Switch to: Custom Domain. Fill the Your Domain field with www.yoursite.com and press Save Settings.
6. Please wait for a few hours for full domain propagation and www.yoursite should be now using your blogspot account.
For more details, please read http://www.google.com/support/blogger/bin/answer.py?hl=en&answer=55373.