Affordable Mobiles offer a range of great deals on contract and prepay mobile phones and manuals.
Choose bonded ADSL, bonded SDSL, Leased line and broadband VPN connections from Managed Communications
Sometimes all the information you need can be found in mobile phone reviews
For which make of telephone do you require an instruction manual ?
(try the link(s) at the bottom of the page if you can't find your manual on the list)
The following link(s) have telephone and manualsavailable, some for free download:-
http://www.virtualoffice.com/store/template.cfm?storeid=1&supportguides=yes
www.tabenterprises.co.uk is a website where you can get a manual for pretty much any mobile phone.
http://www.homephonesonline.co.uk/downloads/default.asp try that for BT panasonic and philips free downloads and also other makes