You can find all the information you need about the NOW albums on the official site:
http://www.nowmusic.com/
The first NOW album (UK) was released in 1983 and NOW 67 is due to be released on 23rd July 2007.
abbie.s : Raspberry Beret by Prince did not appear on the first NOW album. However, it did appeared on the HITS 3 album / tape which was a rival of the NOW series at the time.
The NOW albums were released by EMI / Virgin Records but the HITS albums were released by WEA / CBS Records.