Coding new NPCs

I’ve been attempting to code some new NPCs just for fun, but i’m having trouble getting them to behave the way i want them to, ive tried the valve developer wiki and the mailing list etc (which seems a very tedious way of finding information) I was wondering if perhaps the devs or someone else had a good link to a tutorial that goes into more detail than the valve wiki. Cheers

Founded in 2004, Leakfree.org became one of the first online communities dedicated to Valve’s Source engine development. It is more famously known for the formation of Black Mesa: Source under the 'Leakfree Modification Team' handle in September 2004.