When you first start naim, brief usage instructions will be displayed on the screen.
To get started, type /connect screenname and type in your password when prompted.
If all went well, the big blue status window will hide itself at the top of your screen, and the green/blue window list window will scroll off the right edge of your screen, leaving you in a query window ready to talk to me, naim help. You can tell this by looking at the bottom of the screen: HH:MMpp screenname [Query: naim help].
Type something. Anything you type that doesn't begin with a slash (/) will be sent as an IM. Go ahead and say hello to me.
If you already had people on your account's buddy list when you switched to naim, they will also have windows open for them. If you want to add a buddy, use the /addbuddy command, as in /addbuddy "my buddy". You can cycle through your open windows by using the Tab key, or you can jump to a specific buddy by using the /jump command, as in /jump buddyname.
Take note of the line above where you type, naim may try to save you time by offering to finish what you're typing:
I can finish what you're typing; just press Tab.
/jump Go to the specified window or the next 'active' one
That's it. If there's anything else you need to know, check out the frequently asked questions or ask me on AIM.