This tutorial will help you create your first map!
It's like you are a kakuna, and want to be a beedril. Well, to evolve to a beedril you need to be level 10. Well, this tutorial will take you to level 2. If you keep following the tutorials, you will eventually have enough experience to be a beedril.
Ya dig?
Well, it actually will teach you the basics of source mapping, these tutorials will introduce you to half-life 2 deathmatch's tools.
I hope that you know how to start source sdk up. If you don't... Go to tools then launch "source sdk" or in the new UI, library->tools then "source sdk".
Step 1: Set your configuration to the game of your choosing. For these tutorials I use Engine: Half-life 2: Episode 1, and the game version: Half-Life 2 Deathmatch.

Step 2: Start Hammer, by double clicking the title "Hammer Editor"

Step 3: The window that appears is the hammer editor main window, you can close the "messages" window at the bottom if you want.

Step 4: Open a new map file with File -> New

Step 5: You should now see a series of four separated views.
- Upper Left = Camera View.
- Upper Right = Top View (x/y), You see the x and y axis.
- Bottom Left = Front View (y/z), you see the y and z axis.
- Bottom Right = Side View (x/z), you see the x and z axis.

Step 6: Find the 2d view marked "top(x/y)".

Step 7: Select the block tool

or press Shift+B. Make sure that the drop down menu on the right of the screen says "block".
Then while holding your left mouse button drag out a 1024x1024 cube within the "top" grid.

Step 8: Press enter to create the cube. This cube is now considered a brush.

Step 9: To view your cube, you need to make a new camera, so click the camera tool

on the right side of the screen,
then in the "top" view click, to create a camera. It should look like the following.

Step 10: Now, you can click into the "camera" view in the upper left box. To move the camera use WASD and click to move the view angle.
You can move back until you see a big floating block, Move until you see something similar to this. Most likely it will be wireframe though. So click the camera text and choose "3D Textured Shaded Polygons". And you should now have textures showing on your brush.

Step 11: Now, press the select tool button

and then select the square in the front(y/z) view. Then click with the left mouse button and drag it down until the top of the cube matches with the blue line.

Now we will start to create the walls of your first map.
Step 12: Select the block tool

. Then click with the left mouse button and drag out a 64x1024 cube in the top view, at the left edge of your original cube.

Then in the front view select the dashed cube and then drag its height to 128 units. It should look like this. Then you can press enter to make that cube a brush.

Step 13: Repeat this process, changing dimensions of the walls, making sure they don't overlap, until you have 4 walls, like so.
Make sure that the walls, or floor, do not overlap. That is kakuna work, and you want to be a beedril.
Step 13: Select the browse button next to the texture editor.

The browser should appear, it looks like this. This is the texture browser, it allows you to look for different types of textures to use in your maps.

Step 14: In the filter type: "tools/toolsskybox" This will find the skybox texture. Double click it and the browser should close.

Step 15: Draw out a cube that is 1024x1024 in the top view, and 64x1024 in the side or front view. Make it above the existing walls. It should then look like so. Press enter to make it a brush.

The skybox texture makes it so that when you compile your map, the sky shows. Without the skybox you would have no sky in game. And the skybox also helps to prevent leaks. Leaks are when your map looks into the "void". The void is all of the black area around your map. When you have a leak, the compiler will output that you have a leak. If your map compiles strangely or does not run in game when completed look towards the top of your compiler output and you should see something similar to this.
**** leaked ****
Entity info_player_dea
thmatch (-207.43 317.29 65.00) leaked!
OK, on to the next part.
Step 16: Move to the inside of your room.

Step 17: Press the entity tool

or press Shift+E. Then Select "light" from the drop down menu in the entity browser.

Step 18: Click the wall in the "camera" view to make a light appear. You can alternately click one of the 2d views and then choose where you want the entity to be by hand.

Step 19: Select info_player_dea
thmatch in the entity tool

.

Step 20: Click the floor to place the info_player_dea
thmatch. A player spawn is vital to your map compiling correctly.

Step 21: Run the map with file -> Run Map. If you haven't saved the map, save the map.
MAKE SURE YOU DON'T HAVE SPACES IN THE NAME! Choose the compile options of, normal, normal, normal. And uncheck hdr if it is checked.

Compile window looks like so.

Step 22: Check yo map out!

If it all worked then you have made your first map. If it didn't then post your problem in the thread!
Sometimes in hl2 dm the map closes, and there is a message displayed that says "Client Timed Out". You can just start a new server with your map chosen. Or if you have the console enabled, type "map
yourmapname"