You would be better off with the 640-607 book by
Wendell Odom which is what two of my co-workers
used (in addition to the cisco network academy)
plus boson exams to prepare for their exams.
Just so you know, the material for CCNA certification
is going to get much harder. New CCNA's will need to
know EIGRP, Single Area OSPF, VLSM, WAN (stuff from
CCNP BCRAN), route summarization, etc. The new
CCNA exam should be out probably by Fall of 2003.