Well, actually, 11 top tips - I got to number 10 and thought of something else. Follow these 11 tips to the letter and I guarantee you will get much, much better at chess. Probably.
1. Join a club. The single best thing you can do to improve.
2. Play. Not 5min internet blitz games, but proper, serious league and tournament games where you write down all the moves
3. Review and annotate your games. When you get home after a proper, serious game: (i) add the moves in to a chess programme (Fritz is the best known); (ii) write in your thoughts, comments and suggested improvements, especially about the key moves in the game; (iii) then get the chess programme to analyse the game; (iv) check your analysis against the computer's analysis.
4. Learn some openings. If you are following tip #2, you'll soon realise that you need to know something about the openings. Buy one repertoire book for black and one for white. Don't try and memorise every variation and every note (in fact, don't try and memorise anything), just read through the main lines given in the book and that will give you enough to get started. It will take a couple of years for everybody to work out what your repertoire is, and by that time you will know your openings very well indeed.
5. Buy a book. The best books to get are well annotated collections of complete games. Why? First, because it is enjoyable and doesn't feel like studying at all and, secondly, because it's comprehensive: you learn about the opening, the middlegame, and the endgame and how each stage flows into the next, all at the same time. Here are some good choices to get you started:
Logical Chess, Move by Move, Irving Chernev. The classic recommendation for a first annotated book of games to read. 32 games with every move annotated.
(i) Chess, the Art of Logical Thinking, and (ii) The Art of Planning in Chess - both by Neil McDonald. The first book sticks closely to the Chernev Logical Chess formula of annotating every move; the second skips past the opening moves (there are only so many ways to annotate 1.e4!). Both are good train or bus commuting choices because there are plenty of diagrams and no need to balance a travel set on your lap while you read (not easy and people do tend to snigger).
First Book of Morphy, Frisco Del Rosario. A book which I haven't read, but it looks a very interesting approach, illustrating a series of fundamental chess strategies and tenets through the games of the 19th century player, Paul Morphy.
Most Instructive Games of Chess Ever Played, Irving Chernev (again). My favourite chess book. This has recently been republished in algebraic notation and the instruction and writing that comes with the games is, essentially, unsurpassed.
6. Set yourself some goals and write them down. Any self improvement book will tell you that you've got to have goals if you want to improve and the same applies to chess. If you want to really force yourself to improve, tell everybody at the chess club what your goal is (not recommended for the faint hearted).
And another thing, it's far better to have process related goals (e.g. I will spend 30mins each night reviewing and annotating my chess games) rather than achievement related goals (e.g. I will score at least 4 out of 6 at the next chess tournament). Why? Because you have control over process goals rather than achievement goals.
7. Ask yourself questions. Most of the time during a game, most chess players will spend their time thinking about anything but the game in front of them. If your mind is drifting, you can bring your attention back by asking questions: what are the strengths and weaknesses in my position? what are the tactical chances? what's my plan?
8. Learn to control the clock. Lots of players drift in to time trouble without ever knowing why. Try writing down the time on the clock for you and your opponent after every move on your score sheet and learn where your time trouble moves are. Just writing the time down in this way will probably help by making you more aware of the clock during the game.
9. Learn some endgame basics. Buy a book on the endgames, the simpler the better, and make sure you know what to do at the end of the game. You might not necessarily be a fan of the writing style, but Silman's Complete Endgame Course has lots of material for every level of player.
10. DON'T play internet blitz chess. It's highly addictive and, like any addiction, complete abstinence is the only cure. You won't learn anything from a day in front of the PC playing endless internet games.
11. While we're on the subject of what not to do, DON'T spend all your time studying tactics. Buy a book or computer programme on tactics by all means, but don't just study this to the exclusion of everything else.