First of all, lets make one thing clear- I will not teach you how to make one particular computer game but I will provide you with tips and suggestions that will help you make your first steps in game development industry.
I would suggest you to get started with Game Maker made by YoYogames, which can be found here: Game Maker.
When the program is installed and ready, get acquainted with it’s user interface: on the left are folders which will be used for all the objects, images, audio and scripts you will be using in your game and at the top there is a toolbar with the most commonly used tools.
Where to get started?
First, open Help documentation of Game Maker ( using F1 key or Help – gt; Contents). There are good explanations of how things work around there.
Second, get or make sprites – images that will be shown in your game. Characters, decorations etc.
Third, create an object and name it, give it some apparation ( sprite ) and click Add Event. From there you can control that object- what, when and how it will behave in your game.
Probably the best way of getting started is by checking out the example games that came with the program. They can be found here: Your disk / Program Files / Game Maker / Examples. Open them and learn from them. The one you should start with is “Hit the ball” as it is a really simple game. Start from learning the structure and how objects are built, because Game Maker is object-oriented platform.
Where to publish your games?
yoyogames.com offers Game Maker developers to publish games on their site for free but I’d suggest gamejolt.com as it shares it’s ad revenue with developers.
Where to get extra information?
Google.com for questions, Gamejolt and YoYogames forums for help and advanced tutorials and materials for building games.
Good luck making games!