How do I book beauty salon & ocean liners?

I'm still a relative newbie to cruising, only 2 under my belt and both of those were on Carnival. Can someone tell me how I book appointments at the beauty salon and also at the alternative restaurant ocean liners? Will there be someone in the lobby area or do I go to the places directly? How soon can i do this? For example, if we start boarding at noon, should I make a mad dash at 12:01 for Ocean Liner's and the beauty salon? Any advice is more than welcome.

Thank you!

If wanting a special appointment to get hair done for Formal night, make it ASAP, that seems to be the most busy time for them. As for the Specialty restauarnt, depending on which cruise line, they have different areas to sign up, either do it at the restaurant, or at the front desk in lobby, and Celebrity you can call from your room to book just about anything.

Emerald Seas 1980
Norway 1994
Zenith 1995
Royal Majesty 1995
Century 1996, 1999
Ecstasy 1996
Mercury 1997
Horizon 1998
NCL Wind 1998
Grand Princess 1999
Sea Princess 2000
Infinity 2001
NCL Star 2002
Millennium 2003
Summit 2003, 2004=2X
Sun Princess Nov.22, 2004
Brilliance April 8,2005

Great! It's good to be "in the know". The information is much appreciated! Thank you!