Do I report my nondeductible Roth IRA contributions on Form 8606?

There are no forms to report a Roth contribution. The financial institution, which is the trustee of your Roth IRA, will send you information on the amount in your Roth IRA. They will also send the information to the Internal Revenue Service. Use Form 8606 (PDF), Nondeductible IRAs, if you made a nondeductible contribution to a traditional IRA; converted from a traditional IRA, a SEP, or Simple IRA to a Roth IRA, received a distribution from a traditional IRA, a SEP, or a Simple IRA and made nondeductible contributions to a traditional IRA, or received a distribution from a Roth or traditional IRA.

Can a person make a contribution to a SEP-IRA and a Roth IRA, too?

Yes, you can make a contribution to a SEP-IRA and a Roth IRA. See Publication 590, Individual Retirement Arrangements, for the requirements to contribute to a SEP and a Roth IRA. However, your SEP IRA contribution and Roth IRA contribution can not be made to the same IRA.