Welcome to the amazing world of making tracks for a great auto racing sim !
But as trackediting for Grandprix2/3 is not officialy supported, sooner or later You will find out its not as easy as it may seem at first sight. There are too many unknown factors in the trackfile-format yet, so sometimes the effects in gp2/3.exe are bizarre or simply nasty.
In this place you find information how to proceed and how to shoot troubles. This place is also thought as kind of library, knowledge base. On the other hand You are invited to contribute.
This site does not include user guides for the trackediting programs of Paul Hoad and Vaino Iso-Hannula, but if You understand the described basics and routines, I dont doubt you will find the appropriate menu-calls in the mentioned tools. Btw: I appreciate both programs for their advantages.
One thing is that important that I already mention it here: BACKUP !
It is possible to thoroughly mess a trackfile within a few seconds, without noticing immediately! The trackediting-programs do not feature undo-functionality for all functions, it would be too complicated to implement them. Sometimes You cant even load the track again in the trackeditor. Thats why I strongly suggest to make frequent backups and keep them. The latter is also important, because it may happen, you realize a bug some weeks/months later only, and then You will be glad to have the opportunity to trace it back (exactly this happened to me a few days ago).
After the first suggestion, here a 2nd one: proceed little step by little step, especially at the beginning of Your trackediting career. You have to develope a sense for the traps and troubles. Do check Your track in the sim frequently.
In the writings-section You find some writings that may introduce You to more specific aspects.
In the trouble shooters FAQ You find, You guessed it, descriptions of problems and their possible solutions.
Happy editing !