The generally accepted age for the Earth and the rest of the solar system is about 4.55 billion years (plus or minus about 1%). This value is derived from several different lines of evidence.
(http://www.talkorigins.org/faqs/faq-age-of-earth.html)

It is extremely difficult to define the age at which the Milky Way formed, but the age of the oldest star in the Galaxy yet discovered, HE 1523-0901, is estimated to be about 13.2 billion years, nearly as old as the Universe itself.
(http://en.wikipedia.org/wiki/Milky_Way)

13.6 billion years is the age of the oldest star in Milky way. It is nearly as old as the universe itself."This estimate is based on research by a team of astronomers in 2004 using the UV-Visual Echelle Spectrograph of the Very Large Telescope to measure, for the first time, the beryllium content of two stars in globular cluster NGC 6397.14needed From this research, the elapsed time between the rise of the first generation of stars in the entire Galaxy and the first generation of stars in the cluster was deduced to be 200 million to 300 million years. By including the estimated age of the stars in the globular cluster (13.4 ± 0.8 billion years), they estimated the age of the oldest stars in the Milky Way at 13.6 ± 0.8 billion years. Based upon this emerging science, the Galactic thin disk is estimated to have been formed between 6.5 and 10.1 billion years ago."
"The generally accepted age for the Earth and the rest of the solar system is about 4.55 billion years (plus or minus about 1%). This value is derived from several different lines of evidence."

There are various opinions on the earths age but it thought to be around 4.5 billion years old.
As far at the Galaxy goes it is thought that the oldest stars in the galaxy are around 13 billion years old and the galactic disc is between 6 and 10 billion years old.
Astronomy is a side interest of mine and yes I got an A in it at Palomar College.
The wikipedia article has basic information on the Milky way. Space.com is also a site that gives you information on galaxies, planets. Space travel, astronomy and other space related information.