12.04firewall
I am a novice at Ubuntu (12.04). I have it on my netbook which I use mainly for surfing the net, learning python and remote desktop into my work computer.
Do I need to enable a Firewall type software? If so, what would you suggest, and what are sensible default suggestions?
First of all, the main reason behind Firestarter not being maintained any more is that Ubuntu comes in with the firewall called ufw by default. You can install a graphical interface to ufw by selecting it from the Ubuntu Software Center (package gufw) or by typing
sudo apt-get install gufw
Please note that any and every "firewall" in Ubuntu will be some kind of interface to the iptables. Some of these interfaces are graphical (like Firestarter), some not (like ufw), some are not graphical, but come with their own graphical interface. You will find more information on this page.
Also, please consider the following. Firewall can be of real use if you do understand iptables and the way TCP/IP works. If you do, then configuring the firewall using either naked iptables or some kind of text interface based on config files (like ufw) usually presents no problem.
When Connect to Ubuntu Server from Linux Client Via Terminal, Specify the port Number, Suppose that your server ip 192.168.16.10 (any hostname) ,with port 39
at terminal
ssh username@192.168.16.10 -p 39
where username is exist username on that server you connect , -p : specify the port number.
At Vinagre Client , New Connection , then Specify the hostname:portnumber, 
Best Answer
In most desktop cases you don't need to have a firewall. When you use a router at home, it does already quite a job -- for example, it does network address translation (NAT) such that you only have a local IP -- not reachable from the Internet.
Also, Ubuntu does not open any ports out of the box, so that there is no real danger of anyone trying to hack into your SSH.
Finally, all firewalls actually are different interfaces to the same thing -- the iptables of the Linux kernel.
You really need a firewall if your machine sits in a LAN, with an IP visible for the whole world and you need to open up some ports (for example, you run a server, be that a test web server installation or an SSH server).
Furthermore, a firewall is very useful if you want to limit which addresses are allowed to use an open port on your machine (e.g. you only allow the IP of your lab workstation to connect to the SSH port of your home computer).
Of course, you might want to learn iptables one day :-) However, in that case, learn the iptables and networking first, and then use one of the alternatives which make the life of a network admin easier.