I have been messing around with Nmap lately and I scanned a few systems that I have setup in my apartment. I am scanning from my Linux system which is has Ubuntu 9.04 OS installed to scan my other two computers which are running Fedora 10 and Windows 7. I did a basic Nmap scan just to determine which ports were open on those computers. I have a list of several that are open for each. What would be the first step to attempt to gain entry to one of the open ports on these computers? Second question, do I get a GUI or cmd-line interface when connection to one of these computers through its open ports. I have never done this before so I cannot envision what is next. Any help would be appreciated.