SecondLife

Official SecondLife Website

Official SecondLife blog, to read about new updates and notices.

SecondLife Grid
Second Life Grid is a platform that enables your organization to create a public or secure private space using the leading 3D online virtual world technology. Discover how your organization can create its own space for communication, collaboration and community engagement.

Wiki SecondLife
SecondLife Wiki, to help, awnser your questions, lots of reading material.

Issue Tracker (jira)
The public issue tracker, known as "Public JIRA", "PJIRA", or just "JIRA", is an issue-tracking project management tool. It's used by the Second Life open source initiative to organize issues (i.e. bugs and feature requests) submitted by the Second Life community into a searchable database.

LibSecondLife
The libsecondlife project is an effort directed at understanding how Second Life works from a technical perspective, and extending and integrating the metaverse with the rest of the web. This includes understanding how the official Second Life client operates and how it communicates with the Second Life simulator servers, as well as development of independent third party clients and tools.

SecondLife History on Wikia
Brief history and info about secondlife on Wikia