This is a common 555 timer/oscillator from TI. A classic for all of those first year circuits projects where you need to blink an LED, generate tone, and thousands of other great beginning projects. Google around for a huge list of resources and example projects.
4.5V to 16V supply
8-pin DIP package
Timing from microseconds to hours
Astable or monostable operation
Adjustable duty cycle
TTL compatible output
Sink or source up to 200mA