A while back I posted some guidelines to help learn the correct fingering for playing the major scales, but since then I've added a few more. Here's an updated list:
1. You will ALWAYS start a white note major scale with your thumb in the RH.
2. You will almost ALWAYS start a white note major scale with your pinky in the LH. The only exception is the key of B, which you will start with your 4th finger.
3. You will NEVER start a black note major scale with your thumb. You will most likely start those with your 2nd or 3rd finger.
4. All white note major scales end with the pinky in the R.H. The only exception is the F major scale, which ends with either the 1st or 4th finger.
5. All white note major scales end with the thumb in the L.H.
6. All black note major scales in either hand end with the finger it started with. One exception is the F#/Gb major scale, which can end with the pinky in the R.H.
*moving foward in LH, backward in RH
7. Don't cross until you have reached your thumb. In other words, run all your fingers out.
8. Once you reach your thumb, stop and think which finger to I need to cross over to play the next note.
9. Your 4th finger will almost always play ONLY one note, so if your next note isn't the one to be played by your 4th finger, then you will cross over with your 3rd finger.
*moving backward in LH, forward in RH
10. Don't tuck until you have reach your 3rd or 4th finger.
11. Once you reach your 3rd finger, stop and think do I need to tuck here or keep going to my 4th finger to tuck.