There is a variety of general information on Taxes available from the Community Toolkit, in addition, the following websites may be useful. Tax law is very complex so care should be taken and professional help sought if required (e.g. from an accountant).
HM Revenue & Customs (HMRC) - The main source of tax information, includes a section for Charities and Community Amateur Sports Clubs.
Charities, Trustees and Tax (Charities Commission) - Please note that this is aimed at charities in England and Wales. Consequently the charity law information may not apply in Scotland. However, is does contain some useful information. If in doubt, discuss issues with HMRC; your accountant; and/or OSCR.
Scottish Council for Voluntary Organisations (SCVO) - this website contains a section on VAT & Tax. SCVO also provide a VAT & Tax helpline for SCVO members.