You can not use the TT Online versions or the personal TT 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-Provide...
FAQ for Tax Preparer Requirements
http://www.irs.gov/Tax-Professionals/Requirements-for-Tax-Return-Preparers:-Frequently-Asked-Questio...
Do you need a PTIN (Preparer Tax Identification Number)?
http://www.irs.gov/Tax-Professionals/Frequently-Asked-Questions:-Do-I-Need-a-PTIN%3F
