I just received a Form 5498 for the 2014 tax year. It shows that I contributed to a Roth IRA but not to an IRA, SEP, or SIMPLE account, and that I did not take any distributions from any retirement account. Is this form just for my records, or do I need to recalculate my taxes in some way?
The form is just for your records. You do not need to adjust your tax return. From the article "What is Form 5498":
Form 5498: IRA Contributions Information reports your IRA contributions to the IRS. Your IRA trustee or issuer – not you – is required to file this form with the IRS by May 31. You won't find this form in TurboTax, nor do you file it with your tax return. The copy you receive in the mail is a copy for your records.
It's a good idea to verify that the amount reported on the form (box 1) matches what you actually contributed.