This (from CAB) is probably a good place to start - covers
selection for redundancy (i.e. what basis an employer can decide what posts / who to make redundant - employer can't use redundancy to decide "we don't like you, you're redundant") what processes they have to follow, things like offers of redeployment / re-training and so on.
redundancy pay / notice (employers can have contractual arrangements that are more generous than statutory legal minimum redundancy pay etc, but they can't offer less. not even if they are a charity. some charities seem to think that because the basic structure of the organisation is voluntary, paid staff shouldn't expect their statutory employment rights, which is balls.)
benefits etc afterwards. (don't be put off claiming what you're entitled to, but bear in mind the amount of being poked with sticks by the DWP is increasing)
Some employers offer enhanced redundancy payment if you go for voluntary rather than compulsory redundancy, but it's not a legal requirement (other than in terms of contract law if your contract includes it.)
There's also no legal requirement to invite volunteers for redundancy, or to release all who volunteer. (volunteering for redundancy and not getting it can be pretty damn uncomfortable)
To the best of my knowledge (and may be worth checking, as it was a few years ago I researched it) entitlement to job seekers allowance etc is not affected whether it's compulsory or voluntary redundancy, but some insurance things (e.g. if you've got unemployment protection insurance attached to a mortgage or something like that) do only cover compulsory redundancy.
best of luck
Just a thought - presume your comment about funding means that whatever function it was is being cut? rather than a contract / funding arrangement for provision of that function being awarded to another organisation? If it is the latter, you might be entitled to transfer to new provider. (can waffle more about that if it's relevant)