Sea Monkey is a very good browser , but addition of addons could even make it a more powerful browser .
Let us discuss the various addons for FireFox :
1. Download them all is a very good download manager for seamonkey . It will help you download selected links in a page and it will also help in downloading various photos and images and videos in a web page. It has download acceleration features.
D0download it at addons.mozilla.org( For firefox), a version for seamonkey is available for download at mozdev.org.
2. Seamonkey versions below 2.0 does not have a close button for every tab . So you can add a addon from mozdev.org for putting a close button in every tab.
3. You need a extension manager for managing and uninstalling extensions in seamonkey .There is an addon for that , but Ido not the location of the addon.Just Google for it.
4. Ad block plus is very important addon for blocking ads on web pages , first install this addon and then download an adblock plus filter file from the Internet and add it to adblock plus. This is a popular addon so you will be able to get it very easily . Just Google for it.
5. Flash Block is also a very important addon for blocking flash content in websites .You can save a lot of bandwidth by blocking flash in your browser . To learn more about saving bandwidth go here. This addon is easily obtained and is a free ware just Google for it.
6. Monkey Menu is another popular addon which you can use for having customized buttons
like clear private data button etc.Just google for it.
Also Many of firefox addons will also work on seamonkey