Restoring mozilla's bookmarks

Firefox 3 no longer uses bookmarks.html to store the bookmarks. It stores the bookmarks and the browser history in places.sqlite and no longer creates a HTML backup by default instead there are also JSON backups in the bookmarkbackups folder within the Firefox profile folder.
Check for backups in following path : 
C:\Documents and Settings\<User Name>\Application Data\Mozilla\Firefox\Profiles\<some  folder>\bookmarkbackups


See Lost_Bookmarks (MozillaZine KB)
You can export the bookmarks in Firefox to a HTML file: Bookmarks > Organize Bookmarks > Import & Backup > Export HTML
You can also create a JSON backup: Bookmarks > Organize Bookmarks > Import & Backup > Backup

If migrating to new account , then just copy the latest JSON file to new account's bookmarkbackup folder and restore it in mozilla.
You should restore a JSON backup: Bookmarks > Organize Bookmarks > Import & Backup > Restore-> Choose file
 Restoring a JSON backup will replace all existing bookmarks. You can merge bookmarks if you import a HTML backup.

A HTML backup doesn't support tags and annotations, so if you want to preserve those then you need to use a JSON backup.

Chrome's New Tab Feature on Firefox

Now you can get Google chrome's new tab feature on your Mozilla Firefox. When you open new tab in firefox, then you will see 9 thumbnails of most frequently visited pages, Recent bookmarks, and recently closed pages. So if you had liked this feature on Chrome, and you use firefox as default, so now you can use this feature on firefox also. To get this feature you need to install Google toolbar 5 for firefox.

This will make your life faster on Firefox, at just only one click you will be able to access your favorite links.