1.
Visit http://www.dmoz.org/
2.
Choose the most appropriate category which is fit for your website or blog.
3.
Choose the most appropriate subcategory from alphabets which is fit for your website or blog.
4.
Continue choosing subcategory
5.
Now click on 3rd link ( suggest / submit url) at top of the page.
6.
Read guidelines and rules and fill out form carefully.
7.
Read agreement, press on submit button and wait until website / blog to be indexed within week.