uh-oh...

Road my bike out to work today, did my shift, and road back, lots of rough hills both ways. So on my ride back home today, i come down a few hills. I noticed squealing in my breaks. I get off, look to make sure there's nothing on my break pads and no un even wear on the pads...neither on both...but I look at my wheels, and see that one side is SHINY...meaning that the rim was SHINY all the way around...I dunno what this means. The *left* (when riding) break pad had this little blip on it...when I felt it it didnt feel any different from the rest of it, but it LOOKS different. I have no idea what is going on, but I'm concerned that I'm going to ruin my wheels, and it's something I can't reallly afford right now.