Where to look for Mods, and some useful mods (moved here from General Discussion)
This came up in another forum, I decided to repost the info here.
At this writing, the current version fo Thaumcraft is 18.104.22.168, for Minecraft 1.7.10.
The current and all prior versions of Thaumcraft are available on the mod's Minecraft Forums thread. Azanor is currently working on a 1.8 version, with occasional comments/complaints about the process.
Unfortunately, there are several "pirate" sites which claim to offer "compatible with 1.8 (etc)" versions of mods, without regard for truth: Obviously, you don't want to go there.
The best places to look for mods are the Minecraft Forums' Mods section and the Mods on Curse site, both official and backed by Mojang. (I've found one community site which looks fairly legit, but is not official, so qualifies as "out on a limb".)
There are also specific locations for key base mods:* Minecraft Forge is the Mojang-backed base for most mods. Go for the "recommended" version for your MC version. Only if an official mod post, or discussion on its MCF thread, indicates you really need something else, should you upgrade past that.* Liteloader is a lightweight base for mods that don't need Forge, because they only affect the graphical interface. Individual mods will tell you up front if they need it.* Fastcraft is a specialized mod that doesn't affect gameplay, but backports some of the 1.8 optimizations to 1.7, for a major speed increase. There have been a very few reports of conflicts with other mods, but mod authors tend to deal with those ASAP. (The link is for version 1.20, you may need to go further to the bottom of the thread for newer versions.)* Optifine provides graphical optimizations. It can greatly speed up and improve the experience for vanilla Minecraft and some mods... but it's also infamous for "not playing well" (graphical bugs and crashes) with many other mods: Basically anything which itself adds glowy stuff or other fancy graphics. (Thaumcraft does glowy stuff, so I don't use it.)
Here I will also note several other mods I use. All change the gameplay experience in ways that may or may not be to your taste.
JourneyMap (forum thread) Is the successor to Rei's Minimap, and a major improvement. It provides a HUD minimap, a larger modal map, waypoints with in-game display, and configurable radar (showing mobs, animals,or other players). Its Fairplay edition disables the radar and some mapping in multiplayer, while allowing all features in single-player. It can also be installed on a server, which allows the server ops to limit the use of those features by players. It's very configurable already, and the dev is working on more configuration flexibility.
Chickenbones Mods (thread forum thread) provides several mods for 1.7.10, some of which have been updated for 1.8. All require ChickenCoreMod for common base code.
The big one is Not Enough Items, which provides in-game reference and search for game recipes, including mod added recipes. A bridge plugin provides support for Thaumcraft's Arcane and Infusion recipes, other plugins are available for other mods. It can also tap creative-mode capabilities, though these can be disabled in the configuration file. AFAIK this doesn't need server support.
I also use a couple of other ChickenBones mods which do need server support in multiplayer:
ChickenChunks provides a simple configurable chunk-loader (expensive by vanilla standards), useful for farms, storage systems, and the like.
Ender Storage provides "tunable" Ender chests -- up to 4096 different color codes allow multiple Ender chests, which can also be accessed by hoppers, golems, and so on. They can also be accessed by Ender Pouches from your inventory. The chests are more expensive, requiring blaze rods as well as the usual. (In multiplayer, chests can also be "locked" to a player like the vanilla ender chest, at the cost of a diamond.) I've been using these for my main storage system: Unlike magic mirrors, it's immediately obvious if your system is backing up (and automated systems can back up when their output is full), or your sorting golem is stumped. allowing you to make alternate arrangements. Combined with TC golems, the ender pouches also let you set up "everfull chests" back home, which you can get at from the road. I carry one pouch for "Storage Input" (replacing a magic hand mirror), and another for general resources, including more pouches for crafting materials, farm output, and such. I also use them to distribute charcoal, nether wart, and essentia crystals among various farms.
I use other mods as well: Twilight Forest and Mystcraft (their forums, cheat-sheet on their wiki), but those aren't directly relevant to Thaumcraft, just adding new dimensions to play with. However, both provide a lot of resources: Twilight's world has a much lower ground level (making gold and diamonds significantly more accessible), while Mystcraft gives you unlimited worlds to ransack for resources. Both do provide Thaumcraft ores and nodes in their worlds. Also, Twilight's world is effing gorgeous, with a series of boss-fights and other encounters available, while Mystcraft lets you design worlds more or less as desired, including biomes and materials supplied by other mods.