I don't know where to download any bots, but here are the install instructions.
1. Make a new folder on your desktop and extract all bot files from zbot .rar or whatever rar file you have that includes zbot to this new folder.
2. Open your valve/cstrike folder. 3. Inside your main cstrike directory (where your liblist.gam is located etc etc) Place the .db files. Botprofile.db and the others go here.
4. If the zbot dll you have is named mp.dll rename it to zbot.dll and place it inside your cstrike/dlls folder. 5. Bot sounds go into cstrike/sounds/radio/bot.
6. Now that you have everything in the right place add this to your desktop shortcut : +localinfo mm_gamedll dlls/zbot.dll
If you are not using metamod you can place this as your main game dll in your liblist.gam. gamedll "dlls/zbot.dll"
After this is done right click your liblist.gam and set it to read only. So that counter strike does not edit it and replace your gamedll with the original mp.dll. Use the commands bot_add_ct, bot_add_t, or bot_quota (0-whichever number of bots you desire).
7. You're done.
Taken from Arucard's tutorial from http://cs.rin.ru/forum/viewtopic.php?t=4453