If you have experience with the basic stamp i think you will feel at home working with Arduino.
Of course the programming language is C / JAVA like but the number of instructions are limited so it is very easy to learn. And the basic hardware concepts like digital in and out - analog ind and out - PWM are the same as the BASIC stamp. And the Arduino platform is cheaper than the basic stamp.
The really cool thing about Arduino is the existing community. Thre are litteraly thousands of people working with it, some with a lot of electronics experience, some with a lot of programming experience, and a lot without much experience yet. But if you look around in the forum and in general on the net, there is an asthonishing amount of information available. And there are lots of nice people ready to share and help.