I have a traditional IRA and would like to convert it to a Roth IRA. Is there a fee involved to do this? And is it a simple process?

It is a simple process, generally...you'd just complete the forms required by your custodian (firm that holds the IRA) to establish a Roth IRA and convert/transfer the balance (or whatever lesser amount you choose) from your Traditional IRA. As you probably know, you will have to claim the converted amount as taxable income in the year of conversion.
Check with your custodian on any applicable fees, which may include: annual IRA administration fee (if not already paid for 2015), IRA termination fee, and so on. A number of custodians won't nickel-and-dime you over issues like this, especially if you're going to keep the destination Roth IRA with them.

There probably isn't a "fee" per se (some custodians charge an account closure fee, so you could potentially incur that, though the only way to know for sure would be to ask your custodian, but likely no other "fees"). It will probably just require you to open a Roth at the custodian of your choice (if you are happy with the custodian where you have your traditional IRA, you could use the same one, which might avoid the account closure fee - though again, the only way to know that answer is by asking your custodian) and then transfer the funds from the traditional to the Roth, and it is usually a relatively simple process.

Note that you will have to pay taxes on any amount converted from traditional to Roth.

If you are currently at a lower tax rate, and the account value is relateively low (such that it wouldn't push you into higher brackets), it could make sense. However, given the potential tax ramifications, before you go through with a Roth conversion, it is probably wise to check with your CPA to make sure that it make sense from a tax perspective.