Attention wireless network geeks!

I’m planning to move a two node network plus a laptop to a wireless net with cable modem Net access.

There appears to be a blizzard of wireless net protocols. Some, I’m told, have security built-in. The router has a passcode and the net cards have passcodes, and the codes must match for the connection to occur. Is this secure?

Also, Roadrunner, my cable provider, says I’ll see no difference in Net access speed between wired and wireless because the Roadrunner transfer rate is less than what the network supports. Is this correct?

Information on/links about wireless nets appreciated!