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.

 

Features:

• 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

Documents: Datasheet