A fellow allotmenteer has recommended the following sites so I thought I'd share them.
http://www.hiddeneden.com/free-seeds.aspx - free seeds(have registered for mine already)
http://www.kingsseeds.com – cheapest seeds and good.
http://www.allotments4all.co.uk/ - this site has a forum and loads of tips
http://www.thompson-morgan.com/plants1/gwm.html cheap offers from t and m