Is there any thing to do here and is there any nightlife...or would we be better stayin in Amsterdam?
Thanks. 
Deventer in Holland
Deventer is a beautiful city, but has very little in the way of nightlife. I know three acceptable pubs, that's all.
Possible activities during day include: a cycling tour along river IJssel; making a stroll through the medieval center, including the oldest stone house in the Netherlands; the historical museum (which is really good) and the toy museum; visiting the many churches, in particular Lebuin church. There's plenty to do for a day, but it's a quiet, low-profile tourism.
Thanks for your help.
Think I'll stay in Amsterdam then....now to find cheap accomodation!!! 
[ Edit: Edited on May 26, 2008, at 5:25 AM by dynamo ]
If you wanted to see Deventer and stay somewhere outside of Amsterdam, somewhere like Utrecht might be a possibility. It has more things to do at night, is worth a look in its own right, and has frequent direct trains to Deventer. There are other options nearby (Arnhem has some reasonable nightlife, and a couple of things to see) as well.
I second Utrecht; that's definitely a good idea. Arnhem is also nice, but imo a bit too far away from Amsterdam (90 mins by train).
id go for utrecht too - student town with lots of nightlife and a pretty town to wander around in!
while staying in Utrecht you can still go out in Amsterdam, as they have trains during the night, they go once every hour and it takes about 30 minutes.
Are Trains expensive in the Netherlands?
Not compared to the UK 
There's a link to Dutch Railways in the Netherlands article of TP's travel guide; check there.
Deventer is a nice city to visit for the day, along with Zutphen which IMO is a bit prettier. Arnhem is OK and has possibly the cheapest hotel in the Netherlands:
http://www.goarnhem.nl/nl/hotels/arnhem/10014.htm
which is right next to the Amsterdam - Dusseldorf railway line (you get what you pay for!)
[ Edit: Edited on May 31, 2008, at 10:07 AM by Skylarking ]