I'm posting this mainly for reference but for anyone else documenting or researching bands on Riffipedia this is a list of sites that I've found over the two years on this wiki and just how reliable they can be. Some musical stories will always be a mystery but for those willing to do the digging there's some surprises to be found. For those who want to start digging into a story of that hip new stoner band or some mythical doom act from yesteryear, this guide may be of help with some personal examples applied:
Official Websites - Most of the time this is the best possible source to go by in terms or raw information from the band be it touring, history or whatnot. One common problem, especially with old band pages, is how much of it has been preserved in the Internet Wayback Machine. Some stuff may simply not be captured with some touring or information simply lost because of time and happenstance. Nonetheless the old .com or .net pages, given the band had it, is a great source. Yet sometimes that bio and list of tour dates may be there, with those pages providing all the info needed. This helps an immense amount with label pages as well, which in turn can help other band pages.
Archived label pages - To further elaborate on that last sentence I've found that looking through the label that which a band was signed on to be a solid source when it comes to album release dates, tours, etc. In the case of Rise Above Records that label's early news helped piece together key bits for the likes of Electric Wizard and Orange Goblin while Southern Lord can piece together parts of pages for the likes of Sunn O))), Boris, Earth and more. The same problems with using the Wayback Machine also applies with many pages simply not existing anymore.
Wikipedia - One of the main reasons this wiki was created was for pages not capable of being on Wikipedia. Nonetheless, everyone's favorite online encyclopedia has it's fair share of info depending on the band and can even be used as a rough draft or ground work to building a page. However with some bands (Say, Unorthodox as an example) the information is as bare-bones as it gets. In a lot of cases, Riffipedia pages may have more history and research that Wikipedia depending on the band. On the flip side there's bands like Sabbath, The Sword, Wolfmother and Queens of The Stone Age where all of the heavy documenting has already been done on Wikipedia, with very little that we ourselves can add.
MySpace - Even though MySpace in it's current state is not what it once was at the time of it's prime years almost every band imaginable was using it. Today those webpages are barebones but one thing of use still is the photos section. Some cases the bands have show dates, flyers and release parties still listed in their MySpace pages. A recent surprising find for example was discovering Pallbearer's earliest shows via their MySpace. If it's a band whom started in the late 90s through the late 2000s it's worth a shot to thumb through the MySpace.
Facebook - The current behemoth of the social media world, Facebook is at large a reliable source for new bands. Unfortunately the pages have changed where you cannot view posts by year but usually going into the Events and Photos sections can give a pinpoint into a band's history and achievements. Plus most bands have resorted to using social media pages as their main official websites so it's usually the go-to. Overall if it's a band started in 2009 or later, go for it. If it's a band from about 2012 on up, absolutely go for it. The same argument could apply to Instagram, Tumblr, Blogspot and Twitter pages as well.
YouTube - The current behemoth of video viewing also has obvious purposes, mainly with interviews and rare live performances. That along with adding the albums of added album pages should it see fit beyond a Bandcamp page.
Setlist.fm - The Setlist Wiki is a bit of a weird case but it does serve as a great source obviously for finding setlists. Another key thing in the cases of some bands is that of finding tour dates and piecing together an idea of how long certain tours spanned, along with special events. It can help to piece together the live actions as to what a band did on a specific year. Their page is also pretty strict with major bands so they can be reliable in that context.
Last.fm & Songkick - Both of these being event pages not too unlike setlist.fm, the thing about these two pages (Especially Last.fm) is their bio pages (Usually helping build a basic story of a respective band) and their event pages, which again can help build on tours and special performances. Songkick also tends to have a lot of show flyers and posters on their respective band pages as well.
Encyclopedia Metallum (The Metal Archives) - Personally I've used the Metal Archives to find a number of bands and really it has it's reliable uses. If the band is on there I can easily recommend it for who's played in the bands, release dates and associated acts. One thing to be forewarned in the case of lesser known or independent bands is that of unreliable info or information that simply isn't there. I've seen cases where what they have listed for bands members and band timelines are simply incorrect. But for the basic foundations of a band page it does help a great bit.
Lambgoat - This page has surprisingly been a huge help in finding news tidbits and tours. With news dating back as far as 2001, Lambgoat covers a lot of ground once you can figure out the search options. In the case of sludge, post-metal or most bands signed to Relapse this has been a reliable source for filling out many of the sources. Examples I can personally name where this page did wonders would have to be Keelhaul, Sourvein, Weedeater and Russian Circles.
Blabbermouth - Not too much unlike Lambgoat, Blabbermouth has been a great source for finding any information on mid-level bands in the stoner, desert and doom scenes. With information dating back to 2001, Blabbermouth is a great resource for finding tours, release announcements and other news on most bands if you're willing to sift through dozens of pages worth of archived news. Some bands the likes of Candlemass and Cathedral got built up with major improvements through Blabbermouth.
Doom-metal.com - While I haven't frequently used this source for doom acts this page is an impressive hub of information for bands in the doom genre, expanding to the death/doom, funeral doom and gothic doom side of that world. Their page usually has histories, interviews and more importantly links to official pages. In the right circumstances this page can be wholly reliable.
Stonerrock.com - Rather than the current forum that exists now I've found the original Stonerrock.com lasting from 1999 to 2010 to be a surprisingly reliable source when it comes to finding interviews and a handful of tours. Their "New One To Burn To" showcased new unknown bands in the scene while the interviews archive goes all the way back to 2000 with some acts! I've found some good stuff thumbing through the remnants of their old forums too.
The Obelisk - What JJ Koczan has done for the stoner rock scene elicits eternal gratitude, writing excellent posts on band actions, tours and of course his own reviews and interviews with folks in the scene. His friday written pieces on albums to close the week also tend to capture the history behind those bands. Simply put, JJ is one of the most well-researched people in our scene and it shows, 10000 posts and counting. Unsurprisingly, The Obelisk and it's forum have both been great sources for finding more info be it for well-known bands in the scene or even some unknown gems not yet getting the rub.