First of all what you want to do is Bevel the edges so they are rounded not smooth them. First hold your right mouse button on the object so it brings up the context menu. From this menu select edges. Now select the edges you want to "smooth" then depending what version of Maya you are working with you will want to use the Bevel tool. It is under the Modeling Menu set. You may want to change the number of segments so that your edges have a more round appearance so instead of just using the tool with its defaults select the little square beside the Bevel and a pop up box will appear with a number of options. Just change the bevel value to 3 or 4 then hit Bevel.
Now for your other question what is a uv and how do i select them i recommend getting on google and doing a little bit of research into what they are and how to use them. There are a number of tutorials out there on working with Uv's. I hope this helped and good luck