Take a look at The Interactive Way To Go and the British Go Association's Introduction to the game of Go.

Two players compete in encircling territory on a square board. The board is 19x19 points, but both 9x9 and 13x13 are common as well. Alternating, they move by placing stones of their own colour on empty intersections. Black plays first, then white (except of a handicap game, where black gets additional stones to compensate being the weaker player).
 
If - after a move - any of the opponent's groups have zero liberties the stones of these enemy groups are removed from the board (captured prisoners). A move is illegal if - after any captures - an own group has no liberties.
 
When both players pass successively the game is finished and scored: Neutral points (dame) are filled in, and dead stones are removed. The black and white territory is scored as points surrounded minus the stones captured by the opponent.
 
More via The Interactive Way To Go.

Basically Dragon is based upon Japanese Go rules. With the exception of predeterming the placement of handicap stones, the board size and time limits. These Dragon-suggested defaults do not follow the official Japanese Go rules, but seem to be useful turn-based default values...
 
In short, Dragon

• uses territory scoring based on the players' evaluation of the board,
  
• has no superko rule,
  
• forbids suicide, and
  
• allows the free placement of handicap stones.
  However Dragon defaults to use a Standard handicap placement of stones.

Explain your query in the Go discussion forum. It's good if you mention both what kind of rule you want more information on, and what kind of situation during the course of play it would apply to.

If you want to improve, you might ask someone stronger to play a teaching game with you, or find someone who is willing to play with you and discuss the game.
 

1. For that you may add a post with subject "request for a teaching game" in the forum to look for opponents, or ask there for other resources or places where to get one.
    
   
2. You can set up a game offer in the waiting room, so that other players can join it. Post a game with "request teaching game" as comment. Restricting the level of the teacher would probably be a good idea. To accomplish that, use the option "Require Rated Opponent" and choose a rating range.
    
   
3. The Go Teacher is an account that specialises in teaching go. Teachers provide comments during play and the game may be reviewed when finished. If you wish to start a game with The Go Teacher, please read the information about settings carefully.