The wiki is located at https://trinitycore.info/.

You are can log in using github auth, so no account needed, and help expand it!

Read this before creating a ticket.
If you have problems with TrinityCore installation, read this.

Read Requirements

In case you choose Linux, we recommend to use Debian 10, it's the Linux we use to test compilations.
Remember master branch is beta, only intended for development, we don't recommend this branch to run a server, use git clone -b 3.3.5 http://github.com/TrinityCore/TrinityCore to obtain a playable branch.

When creating patches read:

• TrinityCore Development Standards
• WDB Fields

We suggest you to create one branch for each C++ based fix: on that way you can continue creating more fixes without having to wait to get one pull request merged.
For the SQL files of C++ based fixes the naming schema is: YYYY_MM_DD_ii_database.sql, where YYYY_MM_DD is the date of the fix, ii_database is the ith sql created that day for database. When doing changes to auth or characters database remember to update the base files (/sql/base/*).
For SQL only fixes create a ticket.
Suggestion: When creating one pull request with sql files attached name the sql file by the PR id it will use.
IE: 2015_02_24_14000_world.sql on that way you don't need to update the filename if the filename you tried to use is used after that by any commit on that day.