Her first task should be finish her term as Governor of Alaska, and to do it very well, as she has done up to this point. She then needs to associate with an independent conservative group, such as Heritage Foundation, which would offer a platform and access to the people she needs to recruit as supporters and fundraisers.
After completing her term as governor, she needs to avoid any other official position (Congress, Senate, Cabinet, etc.) for the following two years. Such positions impose limits on where she could go, what she could do or say, and what she could earn. She needs to learn, speak, and write.
She will be a VERY popular speaker and fundraiser for conservative republican candidates at all levels, and she can earn a lot of support by making herself available to them. In 1976, after Ronald Reagan, lost his challenge to Gerald Ford, he delivered the most important and memorable speech of the Convention.
Then he kept himself in the game by being the most articulate (and prolific) conservative spokesman around, constantly comparing and contrasting conservative ideas against the almost daily failures and fluffs of the Carter maladministration. It’s a proven plan, and she could do far worse that follow it.
I recommend a second term as Governor, writing multiple books, giving speeches, building a network, making contacts, growing the fan base, raising money for other Republicans, and running for President in 2012.