Need to start some were in modding right? Why not try the Half-Life modding Kit. This Kit is designed to have all the tools you need to start your own Half-Life mod, simple mods can be made or advance ones like Base Defense with this small set of tools. If you want to start modding Half-Life you should try this.
This addon contains the Counter-Strike 1.6 FGD file, models, and sprites. This does not have a lot in it but is a start for the Counter-Strike edition
what is this mod?
this is a modding kit that will allow you to modify half-life 1, or other goldsource games. READ THE DESCRIPTION