How important it is to notate games?

Do you do it often?

Any effective way to do it?

Do you focus on your own games or you go for famous games as well?

Surely it's a great way to learn "geography" of the board.

Do you mean write the moves down as you play them?  If so your "Any effective way to do it?" is confusing to me.

Or do you mean analyse the game and make annotations?  If so your comment about board geography is confusing to me.

I only record my moves in tournament games.

After you move immediately write it down.  After your opponent moves, immediately write it down.  That's the usual way to do it.

If you want to learn where the squares are it's better to play over master games on a real board than copying master games down on paper.  Physically moving the pieces aids memory I suspect.  Also try to follow the variations in your head, even if it's only 1 move.  Read the move then look at your board and imagine it.  This is the more common way of learning the names of the squares... getting out a board and going through a chess book.

But I guess recording your games could help too when you're just beginning.

As you read through dozens of posts on this and other forums, one of the most repeated items of advice is to replay your games over, especially the lost games, and analyze them - slowly.  Obviously you can only do this if you can remember them move by move (not likely for a beginner) or if you write them down.

I learned to play back in the day when most books were written in "descriptive English" or EN notation.  Today it is almost exclusively algebraic notation or AN.  The easiest way to deal with that is to use a board or computer screen that has the letters/numbers on the side of the board and when you make a move, think "e4" and write it down.  It takes a bit of discipline to learn to do that after each and every move (I sometimes get so wrapped up in the game I forget, even today) but as you get better, you will want to do that as a learning device - one of the best.

I always do it, otherwise you get disqualified. I only do it for my own games... Other games are obviously already written down.

For practical play, I don't think notation matters very much. You can think:

''I am playing Ng5'' or you can think ''I'm putting the knight on that dark square over there.'' 

 When I play with no serious tournament, I don't annotate my games badly. I don't know why, but I want to just recall it when I'm analyzing it at home.

Maybe the reason why I do this is to be able to recall or visualize the game even when I'm not in front of the board.

It really depends on your chess.  If you play a lot of online blitz, you probably don't care much about playing over your games.  If you want to slow down, analyze and get better, or if you play OTB tournament chess, self-study of your games is almost mandatory.

Online chess servers will compile your moves as you make them and you can download the PGN file of your game for study later.  Any UCI on your computer should allow you to save your games in PGN format as well.  Obviously, any PGN game can be re-loaded into your UCI and studied.

in otb tournaments it is very important - I played a player, a higher rated opponent in a tournament and I was winning but suddenly he claimed his pawn was one more move advanced than it was.

so the TD played both scoresheets to the position and found that the pawn was there I said it to be. So I won. Had he had the pawn on the other square he could have promoted and have the win.

also without notating you cannot analyze the game afterwards. even though everybody should be able to remember their own game since they just played it.
to sum up
1. in disputs
2. to analyze

Tks for your detailed replies! Lots of food for thought. I have a very broad view now. Cheers!