i dont remember my passcode for my ipad...where should i start???

If you've forgotten the passcode to unlock the iPa then you will need to connect the iPad to the computer that you normally sync to and you should then be able to reset the iPad and restore/re-sync your content to it (http://support.apple.com/kb/HT1212) - you may need to put the iPad into recovery mode in order to be able to reset it : http://support.apple.com/kb/ht1808

If you do it via a different computer then :

If you restore on a different computer that was never synced with the device, you will be able to unlock the device for use and remove the passcode, but your data will not be present.