Here' what I would recommend:
Level 44
Level 59
Level 65
For your last 5 points, I would spread them between Mental Quickness, Nature's Guidance, and Totemic Mastery depending on what your plans are. If you're planning on raiding at all, Nature's Guidance should get maxed, as well as Totemic Mastery. If you're not going to be raiding, I'd max out Mental Quickness first, and then decide on whether or not to put one point into Totemic Mastery and one point into Nature's Guidance, or just put two points into Nature's Guidance. That's all assuming that you want to stay Enhancement speced. Really, by the time you're in your mid 60's you should just decide what sounds like the most fun for you - Healing, melee DPS, or caster DPS - and then gear appropriately.
Have fun!