Hi fishook,
The name bookwize.co.uk will, in the main, be worth more money in the future if you can do something with it to get people to visit it, and revisit it, and to buy from it.
As it is, it may well be appreciating in value but only very slowly, and from a fairly low base.
If you can learn to put up some simple but interesting pages or more complicated message board system to get visitors talking about and buying books, maybe specialising on the coverage of some of the rarer classics or prizes, then you will be in a better position when you come to sell it.
If this seems a bit much for you at the moment you may wish to "park" it.
One way to do this is to:
a) ask your isp to change the "namesserver" details to for instance, ns1.fastpark.net and ns2.fastpark.net which is a NameDrive account.
and simultaneously you go to Namedrive.co.uk and start an account, and add your domain. (its all pretty straightforward when you start doing it)
and
b) also start an account with sedo.co.uk and add the domain to your account and list it for sale.
Then spend some time at NameDrive adding appropriate keywords.
At least this way your domain may be considered active and in the long term this is better for it's value. You may also get a few cents revenue to help pay the renewal fees every year.
You need also to check a few other things about the domain:
Make sure it is in your name and not someone else's - at the moment it looks like it is registered to someone else.
Call your isp and get it into your name.
You may have to pay £35 for the privilege, or they may pay it for you, if they should have already done that.
Make sure it is always renewed, or else you may find you lose it when you don't want to.
Meanwhile, bear in mind that it is really only worth what someone is prepared to pay for it, as there is no proper regulated market in domains at the moment, and the more you can make it attractive to the buyer (i.e. by developing a clever and useful website on it) then the more it will be worth.
Best of luck,
-aqls-