In this tutorial I will teach you the basics on how to make a map, it will be mostly written and the plan is to put a video at the end. So first thing first, you need to download some programs, those are Valve Hammer Editor 3.4 and Zoner's Half-Life Tools.

After you install and unzip those, you need to configure them. The first time you open up VHE you get prompted a question if you want assistance in setting it up, answer no to that. Go through the tabs and once you find the "configuration" add a new one, call it whatever you like and make sure to add a configuration file to it (.fgd). Some decent ones can be found in the folder where hammer is installed. Now add a texture to your editor, easiest one is halflife.wad from the valve folder of Half-Life.

Once that's done you should be able to create a new map by accessing File -> New. Now go to the 3D viewport and set it to 3D textured. The tools on the left vertical side will be the ones you use mostly. To navigate inside inside the 3D view press Z, to move around press WASD and mouse. To create a new structure use the Block Tool, to make a sculpture out of it use Clip Tool, to make some complicated vertex manipulation use Vertex Tool, to add game entities use the Entity Tool, to select objects use the Selection Tool. When selecting an object in 3D, you can manipulate it only in the remaining 3 2D screens. First click you can move it around and scale it, second click you can rotate it and third click you can drag its whole shape to a side. You should be good to go for starters, knowing some basic English will help you guess what the rest are. Also keep in mind that the map needs to be fully sealed, if you have a hole towards the external world then your map won't compile. On the right side you select the texture you want to use. You need to export your map to .map in the same folder where you extracted ZHLT. Press ALT+ENTER to see an entity properties.

Now the ZHLT part, make a new .bat file with these lines

hlcsg mymap.map
hlbsp mymap.map
hlvis mymap.map
hlrad mymap.map
pause



Okay, if your map compiles then great, if not feel free to ask around these forums. Cheers!