I think that you will be very pleased with your new rattie. They're a lot more interactive than hamsters or gerbils. They want and need attention from you. Sometimes when you get a rat from a petstore, they're not used to being handled, but it doesn't take them long to come around.
Start right away. The first thing I do is sit with my hand resting in the cage and let them sniff me while I talk to them....
Here's a great link about trust training http://www.ratfanclub.org/trust.html
