I would probably miss off the elf bit from your CV, just saying something like Christmas work or something. When writing your CV expand out what exactly you did and had responsibility for in the sole-charge job. Your other experience is all Group Care as far as I can see, so isn't that relevant to nannying though does help to show you have experience of children of varying ages.
Your experience with babies and toddlers is lacking. Can you think of times when you have had experience of caring for babies & toddlers? Such as babysitting for example. Also expand on any volunteer nursery placement you had with that age of child.
I have parts of the NVQ 3 in Children's Care
What do you mean parts ? Can you finish it over the next couple of months?
Currently you are unqualified. This may limit your opportunities. It may also mean that you don't meet criteria for the uni course (have you checked that you can do the course without a prior qualification?). So before considering the Uni course, I would suggest you finish the NVQ. That may mean you need to work/volunteer at a nursery for a while.
Will potential nanny employers consider taking me on?
Not if they need someone who is Ofsted registered. You are not currently registered and depending exactly on what training you have completed you may not meet the criteria for registration.
However there are parents out there who will happily have someone unqualified and not on the Ofsted register. So there is hope.
What wage should I be asking for?
Have a look at what jobs are being advertised in the area in which you want to work. Then consider what salary you need to live on. You will have bills like everyone else, so your salary needs to pay your bills plus give you some extra for savings & pension, going out, running your car etc.
I would have thought from £6 gross per hour upwards. I would expect that you may find that jobs are offering £7 to £10 gross. You may find that it increases to £12 gross once qualified and have a few years sole charge nannying experience - though I'm qualified and have experience and earn under £11 gross.
Try looking at NannyJob: Essex to get a feel for salaries, though alas many agencies don't list salary details.
If salary isn't indicated, ask it before applying as there is no point applying for a job which won't pay your bills. Ask if the salary is Gross (agencies still often advertise jobs as Net as perhaps they think nannies don't understand Gross pay).
How does nanny pay work (as it's obviously not self employed)?
PAYE like any other job. So your employer pays a Gross wage and deducts from that Employee Tax and Employee NI.
Useful calculator: www.mranchovy.com/calc (will do Net to Gross calculation. Helps if you know your taxcode, see your last payslip, otherwise accept the default).
If I used my car for work purposes how would petrol money work?
You log all mileage. I use a notepad in the car to log journeys (work travel only, does not include your journey to/from work). Then say once a month you put in a mileage claim. From 6th April 2011, HMRC approved mileage rate goes up to 45p per mile, for first 10,000 miles. Any pay amount over the approved mileage rate is taxable and reportable on the P11D (your employer does that) thus why most employers will pay up to the limit before it's taxable in my view.
What questions should I be asking potential employees and agencies when looking for work?
Often useful to ask if someone has had a nanny before (I prefer working for people who haven't, so I don't then have to match and exceed what someone did prior). Ask about if the position is likely to be long term or not (always hard to know but some parents may only be wanting someone for a few months or a year).
Consider what sort of family you would work best with - your experience looks to me to be mostly school aged children. That could work out fine, though consider how much housework duties you would be prepared to do whilst children were at school.
Have I got a better chance of finding work if I look for a part-time job instead of full time?
Maybe. Always hard to tell. Personally I quite like working 4-days a week.
Would people be put off if I said that I was planning on going travelling mid-2012?
Yes if they are wanting a nanny for long term. You are forming a relationship with the children and parents, last thing the parents will want is to have to find a replacement after a few months.
If you want to be a nanny, be a nanny. If you want to travel... go travelling.
Just my view of course. Others no doubt will have different views.