I have a new MacBook Pro 13 inch 2.4GHz and I am noticing that the start up timeis about 60 seconds from power on to launching Safari.
Is this an average start up time?
Yes. Your start up time is dependent on how fast your hard drive is, how full it is, and how your OS is running. If you're running a normal 5400 RPM drive with around 50% of the storage space filled, 60 seconds is about normal. A few things you could do to help this out are:
Reset the SMC
Reset the PRAM
Nope. It should be about half or less.
60 seconds is rather long (although mine doesn't do much better...). And their seems to be a lot of people suffering from this problem... (on Macrumors and the Apple Discussion forum are some reports of people with problems like you).
You could boost your Mac performance if you like. Here is a good tutorial how to boost up your Mac Startup process.
And if that doesn't help you out, here is a wiki where they go something more in depth about the start up process.