Can I use TurboTax software to file other peoples returns? Is there software for a tax preparer to purchase without all the fees for each tax filing? for my business.

TurboTax is only licensed for personal use.  Both the license agreement and IRS regulations prohibit TurboTax to be used by paid preparers.

Intuit offers ProSeries for professional use that meets IRS rules for professionals.   Paid preparers  need an IRS issued PITN.

https://proconnect.intuit.com/proseries/

Thank you!

You can not use the Online versions or the personal Desktop Software to prepare returns for clients.  Intuit (the company that makes TurboTax) has three tax software product lines for paid preparers: ProSeries, Lacerte, and Intuit Tax Online. Here are links to their web sites.

http://proseries.intuit.com
http://lacerte.intuit.com
http://accountants.intuit.com/tax/online/

For a new preparer just starting out, ProSeries Basic is probably the most suitable.

And to prepare more than five e-files, you will need to sign up with the IRS as an ERO - an Electronic Returns Originator.  How to become an Authorized E-file Provider…..
http://www.irs.gov/Tax-Professionals/e-File-Providers-&-Partners/Become-an-Authorized-e-file-Provider 

FAQ for Tax Preparer Requirements
http://www.irs.gov/Tax-Professionals/Requirements-for-Tax-Return-Preparers:-Frequently-Asked-Questions 

Do you need a PTIN (Preparer Tax Identification Number)?
http://www.irs.gov/Tax-Professionals/Frequently-Asked-Questions:-Do-I-Need-a-PTIN%3F

Can I use turbo tax to complete my grandchildrens’ taxes.

If you are using the Online version you can only do 1 return per account.    But you can use the same email address for 5 accounts. To do another return log out of your account and set up a new account and new user name and pay any fees again. That's why it's better to use the Desktop CD/Download program. The Desktop program can do more than 1 return and efile 5 for free.

How to start another return in the Online version
https://ttlc.intuit.com/community/using-turbotax/help/how-do-i-start-another-return-in-turbotax-online/00/25596

Or try the Free File website. Turbo Tax Free File website is free for federal and state. And has more forms than the Federal Free Edition, like the full 1040 return and Schedules A, B, C , D, E, F, EIC, H, K-1, SE, etc.

To qualify for the Tax Freedom website you just need to meet one of these 3 things
AGI $36,000 or less
Active duty military with AGI of $69,000 or less
OR qualify for EIC (earned income credit.)

In order to use the Turbo Tax Free File, you have to start it at a special website. If you use the Sign In button on the top right I hear it brings over your work.
https://freefile.intuit.com