The SWL forums have moved onto the funcom domain along with other funcom games. However given how funcom were a bit late to start these up after the relaunch some people still use Reddit instead as that's what was available at launch.
Secret World Legends: Leaderboards
Want to know who is in the top 100 for Draug kills, or who kicks the most ass in Stonehenge? Check out the official SWL Leaderboards!
SWL Discord Channel
The official SWL Discord channel is frequented by devs and community manager so if you want the latest news about what's going on with SWL, this is the place to look!
Much of the information you may expect to find on the forums can also be found here, including some very useful guides.
Whenever I'm having issues such as not being able to log in this is where I go to check first. Most important announcements about the game go out here. Also if you're interested in what the SWL team is up to you can check out the accounts of the community managers Andy and Spynosaur.
On TSWDB you can find mission guides, lore (or legends as they're called now) locations and much more. Personally I would recommend this over other similar sites simply due to the quality of the content.
Just as TSWDB this is a page which is in the process of updating their content for the new version of the game. CryGaia is more of a wiki than a site for guides in the sense that it tends to document a lot of information about the missions such as mission tiers and dialogue rather than telling you how to complete the mission.
Holosuite Media - Beyond the Veil
Moving away from the guides and into community news. Beyond the Veil is a weekly podcast with a group of people discussing the game. Occasionally they bring in Funcom employees who are involved in the game for interviews about new content and the future of the game. These podcasts are usually live streamed on Twitch and can be listened to after on the holosuite media website.
The Badgers was an initiative started by Spiderbaby and Simond in TSW to make all the 10k monster kill achievements accessible for all players by organizing group farms and documenting information about how to hunt monsters. There have been some updates to the website since the SWL launch.
For the roleplayers this is a resource for news and events concerning roleplaying in SWL.
Reddit - How to... by MerlinAesalon
These seem to be the goto guides for how to play different roles in SWL. They discuss some key concepts of the role, how stats work and what type of gear you should probably be using.
Gear and Theorycrafting Spreadsheet
Contains information on for example how certain gear pieces will influence your overall combat power. Useful if you want to compare different pieces, see how your glyphs stats may look at a higher lvl or simply to see what items you can actually obtain in the game and where.
Lists everything you need to know about your agents. Where to get them, what bonuses they give and so on.
I'm sure there are other valuable resources out there. I know a few of them can be found within some of the links above even. If there's something you feel is missing that should be here, let us know!