Debian newbie woes

I've installed Debian on an old computer I had lying around, and while the webserver seems to be working correctly, I am getting "Connection refused" when I try to use PuTTY from my Windows machine. Ports seem to be forwarded correctly to it.

Questions: On Debian, how do I check that sshd is running? It doesn't look like it is. How do I restart it if it isn't, or failing that, install it using aptitude.