How to improve

Not necessarily. If you're testing a new line / opening, blitz is a great way to help you quickly adapt to its ensuing variations.

You'll never regret Nimzowitch's My System as a decent intro into positional play, also if you're quite happy investing money into books, Seirawan's Play Winning Chess series is fantastic, the tactics one would be well worth your money.

I think observing other people's games is a very good practice for two reasons.

1) You can't make a move so you can consider the impulsive moves then decide if they're good or bad without automatically making them. This has always been my biggest problem (especially otb), and it's only recently I've managed to almost wipe them out (again otb).

2) I also think it can be more beneficial than reading through master games because there isn't that temptation to go to the next move, although if you get something with good analysis (I like Alekhine's personal collections of games, even if they are a little old now) it's a toss-up. To start out, before you start analysing your own games I think it's worth getting at least one collection of well annotated games and seeing why the moves were made (as well as reading through a tactics book). Actually make the moves on a board and look at the positions before moving onto the next move and see if you can work out why the move was made before reading the annotations.

true, but not yet at your level--the recommendations regarding tactics should come well befor this book.

I think it's useful, especially the first section, it drives home the importance of different pieces and how they should be used. In my opinion I would have benefited a lot from knowing how the pieces are intended to be used in all aspects of my game, which I think is why I saw a rating boost when I got into Silman's Complete Endgame Course (maybe wrong with the title, think I could do with another look at it :) )

 My System isnt suitable for beginners. It would be like jumping into the deep end of the pool before knowing how to swim.

I  recommend you study and master the basic checkmates and all the typical checkmates (there are 23 or 24 different classified types) before you proceed to learn anything else it's important to know them so you'll able to see them ahead and apply them without any loss of time when they occur in your games and to avoid being a victim when your opponent tries to spring them on you.

This is called Legals Sacrifice it actually occurred in a game of mine 2 months ago it's a well known 200+ year old mate but Black a young Player at the Chess Club did not know the rational behind it and he got caught don't laugh I've even caught adult beginners in their 40's with this who moved too quickly.

 You have to meet me ;))) and then you will become a  grandmaster.

 no, really,

If you analyze, you have to put these questions yourself :

 1.Where is my weakness, because the opponent can strike there?

    How can I move to remove this disadvantage? What s my counter move?

2.That s not all!!! You have to think strong, strategic,tactic and conceptionfully.

That means, it doesn t reach for you to be satisfaith with one move, which defenses your weakness!! YOU HAVE TO CALCULATE, COMBINE MORE MOVES THAN OPPONENT (strategic,tactic and conceptionfully).

3.Your moves have to give the reason what you are playing, that means to be conceptionfully.....The figures have to stand in the middle game and at the end so, that your position to winning of game, for help take some chess literacy, where you can find grandmaster s games with COMMENTS, its very important to understand reasons why that move is the best or strongest......

4.Go back to the first point....Think about it how you would play if you would be at opponent s side. THAT S THE PRINCIPE OF CHESS MASTER.

5. If you are 100% sure that the opponent can t mate you or take your the most important and valueted figures or sacrife some his more valueted figures to mate you or sacrify for taking of your more important figures or better strategic and tactic position in the middle and endgame, YOU CAN ATTACK!!! 

6.THE ATTACK IS THE BEST DEFENSE, BUT MUST BE BASED ON THE PERFECT DEFENSE.....

I did the same question..have a look!

sorry..I forgot the link.. http://blog.chess.com/EnGliSHCheSsPlAy/how-to-improve ..HAVE A LOOK! :)

"another question: if you're not a good player to begin with, is blitz completely useless?"

I assume by Blitz you mean 5 minute games?

If that's the case then no it's not completely useless. More experience and exposure to chess is a good thing, provided you learn from it and don't create bad habits.

In my opinion playing a single 30 minute game that you analyze would better than a handful of blitz games.

I second Webhead's comments, especially the part about tactics.  Additionally, I recently discovered evidence to support the training method of intense repetition of sets of tactical problems, and I am using this method myself (ct-art program).  The idea of repition is recommended by de La Maza in "Rapid Chess Improvement" and supported by Dan Heisman (Novice Nook at www.chesscafe.com). 

For myself, I found the book, "Chess Tactics for Champions" by Susan Polgar and Paul Truong very helpful.  My game play has risen to a higher level because of it.