HMRC have developed an online interactive format for submitting tax returns and included lots of links to services and products for small businesses- helping them to get their tax right, first time.
Guidance on what you need to do for tax and National Insurance purposes when you start up a business can be found at the HM Revenue & Customs website.
They also provide a wide range of help and support to help you handle your responsibilities to HMRC easily and effectively, available at this link.
A calendar of Key Tax deadlines is available here.
All businesses that turn over more than the HMRC 'VAT threshold' each year need to be VAT-registered.
An introduction to VAT is available at the HMRC website.
A comprehensive guide to VAT, with everything you need to know about registering with HMRC to submitting VAT returns and staying compliant is available to download at this link.