This page will help you get started with mapping and level design by listing the thing's you'll be required to download and provide a little information on setup and things to pay attention to.
Tutorials and Walkthroughs
How to install and set up all the essential programs to begin creating custom user content (for example maps) using GTK Radiant 1.4.0 for Jedi Academy.
The RichDiesal Mapping University / RichDiesal's JK2Radiant MapSource was regarded by many across the community as the best set of tutorials for beginners and advanced mappers to learn from. Some time in 2010 when Map-Craft went down, RichDiesal's tutorials went down along with it. But now we have revived it thanks to users that kept backups! Please note that some images and links still do not work, as some files that were hosted on Map-Craft were not recovered. All the tutorials should still be usable and doable.
MUG's Video Tutorials
This series will teach you everything you need to know to make maps from the ground up.
JKHub Mapping Tutorials
There are many tutorials that have been written exclusively for or provided to JKHub by various members and mappers. These can be truly invaluable to anyone that makes maps for the Jedi Knight games. Chances are, if you have a question, they can be answered by reading or watching these tutorials.
Mapping for Single Player
Redsarus shows us how to map specfically for single player mode, by creating a mission based map complete with scripts, objectives, and NPCs.
World of Level Design
There are many wonderful sites that have great tutorials on level design. World of Level Design ranks up there as one of the best resources for learning how to design maps in a logical and fun way.
Learning the Q3A engine
Q3Map2 Shader Manual
If you plan to take full advantage of shaders (which you absolutely should) then this will be extremely helpful.
Advanced Portal and Hinting Optimization
Learning the technical side of what you're working in can be very rewarding.
Other Helpful Links
MapCore is a great level design community.
A Guide to Level Design
A great guide that gives the ins and outs of designing maps.
Designing Multiplayer Maps
This is a small handbook that explains the logic and methods used to design maps for multiplayer game modes.