I have a IM program that my friends at school want me to host. Its a standalone jar app. I've looked at hosting options and it seems as though I'll have to use a JSP. Is this neccessary and if so can anyone point me to a good tutorial or something to get me started? Else, does can anyone tell me where I can get a host that'll host the program for me?
It does not have to be a JSP. A standalone app can be a server. It's already running that way, right? When you say your friends want you to "host" it, I assume you mean they want you to make it available on the internet. All that's required for that is 1) Your app has to open a server socket to listen for incoming connections, which I assume it is already doing, and 2) It has to be running somewhere reachable via public IP address.
For #2, you either need to be able to port forward from your home router (assuming it has a public IP) to your home computer, or rent a host from a service like godaddy.com.