Welcome to the ESF forums.
First of all, You need a list of things:
1.)a legally purchased copy of Half-Life/Counter-Strike/Day of Defeat
2.) Steam. you can download steam at
www.steampowered.com If you are using WON half-life, the ESF team said they can't help you out, because they are now making all their ESF versions specifically for steam.
3.)ESF, the current version is 1.2.1 Look on the files section of the main page. (
www.esforces.com )
then run ESF via steam and click "find servers" and you are set.
If this doesn't help, try reading the stickies at the top of the forums, if that still doesn't help, post in here and I, or anyone else will try and help you out.