Here is an easy tutorial on how you can build a round button for your web site using adobe photoshop. Create a new file (File>New) at 72dpi, RGB mode and create a circle using the eclipse tool. Apply the following effects on the circle layer and your button is ready. We iclude the .psd file below so you can build your button upon ours. The light blue we used for the gradients and stroke is #27cef8.
Download the source .psd file. Your button after the steps above should look like this below