It's not bad, but the first five points you're going to want to spend will be in Improved Frostbolt. It may seem like not that big of a deal, but in WoW half a second can make a huge difference. I'd suggest looking at
this link. It's in our Mage sticky and it's a guide to how useful the frost talents are for PVP, Raiding, and Solo.
I'd suggest something like this:
link to 60. Always take just enough points per level to make it to the next tier, and then fill in the extras when you don't have enough points. After 60 I'd recommend getting Arctic Winds and Brain Freeze, and maybe Frost Channeling and Improved Cone of Cold if you want. You can also dip into Arcane or Fire if you'd like after AW and BF, but that's completely up to you.