You would enter it under the Investment section. Please follow these instructions:
In TurboTax Premier online edition,
1. After sign in, select Take me to my return
2. At upper right corner, search for this exact phrase: sold second home
3. In the search results, click Jump to sold second home
4. Answer Yes on the screen, Did You Sell Any Investments?
5. Follow step-by-step instructions, on the screen, Choose the type of investment you sold - select Everything else and follow the prompts.
When you sell mineral rights, it is treated as a long-term capital gains sale (IRC 1231) as long as it has been owned for more than one year.
If you acquired by inheritance, then there isn't any "cost" to you on that date. However, the value of the asset as of that date must be determined because the rules state that your basis is established by the value of that date.
You need to secure a "valuation" of the asset as of that date and the IRS has criteria to establish that value. Mineral managers or valuation experts can handle this pretty easily, even going back in time. They prepare a report and thus "document" the basis.
