Could you provide a little more information on what you wish to set the phone up to do specifically.

thanks for removing the poll thing I couldn't work out how else to start a blog!!!
All I really want to do is set up emails - I have a giffgaff sim with it.
Many thanks if you can help further

Some of these may help http://community.plus.net/library/category/email/ but can you explain what the problem is.
For example are you trying to access and send emails from your phone using the Plusnet servers or send them using the mobile supplier server assumed to be O2
Have you looked here http://community.giffgaff.com/t5/Help-Ask-the-community-got-stuck/problem-setting-up-email/m-p/29075...

thanks for your help. I'm still struggling but I'll get there in the end - somehow!

There's a good step by step guide here http://business.mobistar.be/go/en/soho/configure#/Nokia/C5-00/E-mail/manual-configuration/
I think the main things is to select 'Other' as the type of email account. That will let you enter a separate username and email addess. You need that since on PlusNet your email address will be something like mailboxname@username.plus.net and the corresponding username will be username+mailboxname. I would suggest you use IMAP rather than POP3 , use imap.plus.net as the incoming server. For the outgoing server you are probably best using the o2 one , smtp.o2.co.uk ( I think! )
Edit: I'm not sure if the o2 smtp server will require authentication. If it does then you can try using relay.plus.net instead but that will require you to authenticate with your PlusNet mailbox username and password.