http://www.gamefaqs.com/ds/989552-pokemon-black-version/faqs/61075 HM/TM list
TM24 - Thunderbolt Location :: P2 Lab TM53 Energy Ball Location :: Rt. 13 TM80 Rock Slide Location :: Fukiyose Cave this must be a japanese name >.> TM 71 Stone Edge Location :: Training Cave TM14 Blizzard Location :: Sekka City PokeMart; 70,000 Yen again japanese >.> stupid faq maker TM26 Earthquake Location :: Ancient Castle
Im gonna help you with Earthquake since I had trouble with that one. First of all, you need to have beaten the E4. Then you go the desert. You have to go in the same opening as you had to before, I believe the one with the Darmanitan statues. Go to the same spot as you had to do before, only this time, there is a new door. go thourgh it, and find the Sage. continue on and youl find it.