npn transistor question

hi i want to use this surface mount npn transistor, and i want to work out the base resistor to use, could someone tell me the max voltage and current that can be applied to the base to turn it on? and what symbols to look for? thank you

http://www.rapidonline.com/pdf/47-3372.pdf

You don't normally apply voltage to the base, you apply current, hence the base-resistor.

I presume you will be using a common-emitter switching circuit? IE emitter to ground, load to collector, base via resistor to Arduino output pin...

The device has a gain of 100 or so at sensible current levels, so in order to saturate you want the base current to be MORE than collector current / 100. Say you have 200mA load, the base current suggested by the gain is 2mA. Lets ensure it saturates by giving it 5mA. The base voltage will be about 0.7V, the output pin 5.0V, so the base resistor will need to drop 4.3V at 5mA, suggesting a value of 860 (next standard value is 820, but its not very critical).

But we don't know what you're going to use this transistor for...