Currently I use some freeware programs to play Go. They're enough for my level at the moment.
I've been playing the 9x9 version of Go for the past few months to practice, mainly keeping an eye of good eye shapes. I got the courage to do 19 x 19 version recently.
So I picked up some tips from reading most of Go For Beginners by Kaoru Iwamoto. It definitely helped! I don't profess to be much more than a beginner, but I paid attention to opening shimari, keeping groups alive, abandoning obviously lost stones, avoiding false eyes, and there are some ko fights toward the later part.
The game is currently unfinished, but I got so impatient I just wanted some advice!
I started the game as Black....
http://www.filedropper.com/cel70gogame
It's a small file, about 30 MB. I might be playing absolutely terribly, but then, that's a good way to learn. I was pretty useless at chess at first, but after some years of studying chess books and getting a strong player to critique my games, I improved greatly.