Bearded Dragons:
Forums — BeardedDragon.org. If you have a question about your beardie on anything from health to housing, this is the place to take it. I usually get a response within 24 hours of posting.
Facebook — Bearded Dragon Obsession. Bearded dragon groups have a tendency to err on the side of critical and highly aggressive, which can be very discouraging for new beardie owners. This community was created to combat those stereotypes and approaches beardie husbandry with open minds and a wealth of knowledge. Be sure to read the rules, though!
Morphs/Genetic Mutations — Here B Dragons. If you want to know more about bearded dragon colors, patterns, and other genetic traits, Here B Dragons explains it thoroughly.
Ball Pythons:
Facebook — Ball Python Enthusiasts has solid information, if a bit rigid. Enter willing to receive constructive criticism, and you’ll learn something interesting.
Forums — Ball-Pythons.net. Their BP Husbandry forum hosts a long list of extremely useful “sticky” threads. I recommend giving these a read-through when you have a chance.
Blue Tongue Skinks:
General Information — BlueTongueSkink.org. This is the best organized, most comprehensive site on reptile care for blue tongue skinks I’ve found yet. And that’s saying a lot, since there’s not a lot of information out there…
Facebook — Blue Tongue Skink Enthusiasts. Great community for all your questions about caring for BTS. Also the most informative blue tongue skink resource around.
Crested Geckos:
General Information — Moon Valley Reptiles. This breeder has collected and published a treasure trove of information on everything from crested gecko “morphs” to terrarium design to breeding advice. If you have a question we can’t answer, MVR is the place to go.
Facebook — Crested Gecko Network. Friendly community, lots of cute crestie pics, but lots of good information too.
Green Iguanas:
General Information — Melissa Kaplan’s Green Iguana Care Collection. This woman has spent years studying green iguanas and has several published works regarding their care and behavior. It’s a long read, but 100% worth it.
General Information — Green Iguana Society. Everything you need to know about the realities of keeping one of these popular but commonly mistreated lizards, from dietary needs to rescues in your area.
Leopard Geckos:
General Information — Lizardbeans on Tumblr. Solid information with helpful insights into leopard gecko keeping.
Facebook — Leopard Gecko Care and Advice. Extensive experience, great files, and active members. Strict group rules and a stricter policy against cohabitation, heat lamps, and all types of loose substrate. Those who join should be able to take constructive criticism.
Facebook — Leopard Gecko Network 2.0. Friendlier than Leopard Gecko Care and Advice, but with fewer and less active members. Group rules are strict, but fair, and the files contain excellent information.