It helps to have a descriptive topic name.
The @ in the SteamApps username is actually a problem, so it's good you don't have one of those older accounts.
Steam is installing Counter-Strike to the correct folder. You see, it stores base game content in it's own cache files (GCF) which are in steamapps, and then all customized content, mods, etc, are stored in steamappsaccountnamecounter-strikecstrike or half-lifevalve or something. Your Cstrike dir is where all custom maps and content need to go, valve is just there because it's a HL-engine based game.
To install Half-Life, just right-click the Half-Life Lambda icon shown in your "My Games" list and click "Install Game" from the contextual menu that pops up. Wait for it to download, and then you're good to go.