If you need help with your account or have questions about the game, you can visit the Mojang support center for frequently asked questions and also the ability to contact Mojang for assistance. You can also contact Mojang support via Twitter @MojangSupport.
If you found an issue with Minecraft that you think may be a bug, check if it has been reported to the Mojang bug tracker. Before you submit a bug report (that hasn't already been reported!), be sure to follow the submission guidelines.
For statistics and solutions for common crashes in Minecraft, see the index of crash reports that have been collected.