is it important?if yes, suggest me some free link submission sites.
You want to more than traffic your site than you submit your site with high page rank dofollow social sites.
1. Delicious
2. Digg
3. Folked
4. Myhq
5. Reddit
6. Yahoo bookmarks
7. StumbleUpon
8. Slashdot
9. MyLife
10. Sitebar