Ubuntu 9.04 is to be released on April 23, 09. Not knowing your situation, it
may be better waiting for 9.04 and getting The Official Ubuntu Book 4th edition.
From what I understand that will be a major upgrade, lots of problems will be
fixed.

The Official Ubuntu Book was first published in August 2006.
2nd Edition July 2007
3rd Edition June 2008
Surely there will be a 4th edition.

Link to the publisher
www.informit.com/.../index.aspx\
t&searchorder=Relevance&query=ubuntu&pc_start=0&pc_size=10&searchgrouptype=All&s\
earchimprint=All