Many people find some the mailing lists to be way too busy and the volume of mail can be daunting. Almost all of the lists are available for reading without subscribing via the web: http://docs.freebsd.org/mail/current/
The links to each mailing list contain the current week's postings and its content is continuously updated. The online version is archived Saturday night/Sunday morning and then starts over. If you want to browse old archives in threaded format, they can be accessed thru the parent directory: http://docs.freebsd.org/mail/
Personally, I find reading the lists in this manner preferable to subscribing to each list and managing it locally. Once I found my favorite lists, I made a local document which contained links directly to those lists so that they're just a click away; for example:
freebsd-current - Discussion concerning the use of FreeBSD-current
freebsd-doc - Creating FreeBSD related documents
freebsd-hackers - General technical discussion
freebsd-questions - User questions and technical support
freebsd-stable - Discussion concerning the use of FreeBSD-stable
freebsd-announce - Important events and project milestones
freebsd-advocacy - FreeBSD Evangelism
freebsd-ports - Discussion of the ports collection
freebsd-ports-bugs - Discussion of ports bugs
freebsd-security - Security issues
freebsd-gnome - Discussions concerning The GNOME Desktop Environment
I've also made it a habit to save copies of posts that are of interest to me for quick reference. It seemed to be much easier than trying to find it again using a search engine.
I've found that reading the lists on a regular basis can greatly add to your knowledge. Once you find something, try reading the manual page on it. It takes a little practice to develop some skill to read and understand manual pages (and often several readings of the same thing). Manual pages are written primarily as reference documents and not tutorials. Once you get the hang of them, they are a valuable resource.