Sites that can help

HMRC - Tax advice, National Insurance advice

Companies House - Registering your Business / Company

Federation of Small Business - Good help lines and membership benefits.

TTNC - Business telephone numbers and call forwarding service

Xero - Beautiful accounting software

Capsule - Easy, online CRM (Customer Relationship Management) for doing business

Highrise - Small business CRM, Web contact manager

Google App's - Web based email, calendar and documents for teams (free)

Skype - Online chat (free)

Mailchimp - Easy e-mail newsletters (free version)

XMind - Mind mapping and storming (free version)

Dropbox - Online file storage (free version)

Inkscape - Drawing package (free version)

Gimp - Image manipulation (free version)

OpenOffice - Free office and productivity programs (free)