However, there are some changes to the standard setup. There is a huge tutorial setup in the Minecart Ministry Building, north of the Cathedral, next to the Sportsground. It shows you all the possible stuff you can make. Please check there before you ask what you can do and how block work. Here is a quick overview:
But there is more. Here is a complete list:
|Black||Spawn, pickup, and launch in priority directions as available North > East > South > West|
|Purple||Spawn, pickup, and launch south|
|Light Blue||Spawn, pickup, and launch west|
|Orange||Spawn, pickup, and launch east|
|Cyan||Spawn, pickup, and launch north|
|Dark Gray||Spawn and launch|
|Yellow||Kill minecart and eject|
|Brown||Stop and launch|
Also, powered rail will stop the cart when powered and re-launch it when the power is off.
There are so many combinations of block configs possible. If you need a specific combination, I can use one of the currently non-used colored wool to create a special effect. If you ask me for one though, make sure that you tested it yourself. I will not do that for you.
Please be aware that if you stand on a track, a passing minecart will push you out of the way. If you climb around on a high minecart track you might die from falling in that case.
Do not build any permanently running minecart or redstone system. Everything that is performing an action has to stop itself after a minute or so. Stuff that continues running slows down the server. Violating this is an instant ban. I have a command now that allows me to kill all minecarts on the server. If there is lag, I will use it immediately. Also there is now a timeout and all empty minecarts will get destroyed after one minute. Since you can spawn them with a diamond block that should not be a problem. Be aware that chest minecarts are also destroyed WITH CONTENTS.