Types of Skins
Rainmeter skins fall into two main types: system info and information display. The closest thing to an input skin is a Notepad/To-Do List, which comes with many skins. I'll run down my particular skins for specific details.
The clock is located at the top. Below that is the CPU and memory meter. The inner circle lights up slowly as memory is consumed, filling counterclockwise, while the outer ring fills and expands clockwise as the CPU load increases. There is also a meter showing where there might be spikes in CPU use.
Below that is the C: and D: meters. As you can see, there are two halves to the inside circle. They flash during disk I/O, while the right half flashes during reads and the left half during writes. The outer ring is a reflection of the disk space consumed and there is both a percentage of free space and a numerical display.
Below that is the network meter, with the inner circle representing upload speeds and the outer ring representing download speeds, along with a meter showing recent activity. Below that is the wireless strength.
There are other system-monitoring tools available, and you can use third-party DLLs to call them for information as well. So you can use Motherboard Monitor 5 to keep an eye on system temperatures and fan speeds, which is something important for overclockers. The Rainmeter documentation will show you how to make calls to those DLLs.