adesklets has an entry on freshmeat. It usually gets updated only hours after a new release of adesklets is out -- freshmeat also provides opt-in email notification.
Many peoples maintain desklets-related material online: Mike Pirnat (see "geek stuff"), Diego Essaya (darcs repositories), Dark Liquid (see the wiki), Mark Bokil (see the "Desklets" section), Julian Swagemakers, Michael Willigens, Jean Baptiste Favre, Xavier Janer, and Antonio Cuni (subversion repositories).
External forums and wikis
Many specialized places have a lot of adesklets-related Q&A too, often not indexed by search engines. Let's mention: Arch Linux discussion forums, Gentoo discussion forums, Ubuntu forums (there is even a dedicated thread and howto over there), Xfce forums and LinuxQuestions.
External help for non-english locutorsHOW TO: Installation et utilisation d'adesklets sous Ubuntu (in French)
adesklets: Uma leve e funcional ferramenta de displays (in Portugese)
Alternatives to adesklets
Many FOSS softwares have similar purposes than adesklets (the main differences are tentatively outlined in the official documentation, see "What is adesklets?"): gDesklets, SuperKaramba, GKrellM and Screenlets.
A common misconception is that gDesklets and SuperKaramba are respectively Gnome and KDE specific: that's not true, as they will both work with any windows manager. Not all people have the same tastes and requirements: find out for yourself the software that suits you most.