Deebyshirelady I had a lot of experience with kids but social worker felt dh needed a bit more. We adopted 2 years ago and started process around 20 months before that. We have a birth child, at the same time aged about 7.
Dh had had experience of working with kids and adults (mostly adults and kids of wrong age) with special needs and probablu far more relevantly experience of helping in church creche with under 5s.
In the end this proved enough, although dh did sort of offer to help at Brownies. Dd was at Brownies.
I feel part of this is:
A genuine need for you to know what it is like being around kids, especially not kids from within your wider family (e.g. even having a birth child/experience with my nephews - which I am sure we mentioned! was not considered enoug) because it was considered important for us to know children outside the family.This was our experience three and a half years ago.
Also feel IMHO that adoption services want to see you making an effort for this. Sorry if that sounds strange but I expect others will agree that sometimes adoption services do just want to see you trying!
Lastly, you may genuinely learn things of use.
Try local nurseries. They may be interested in your volunteering. This does depend on you being free to do it. My workplace have always been flexible allowing me short bits of time off to do different things, (eg courses) if I made up the time or took it as leave. Obviously a two week stint can just be holiday allowance.
If no nursery will have you (Don't be offended they may get lots of offers) try toddlers groups, pre schools and schools and consider church creches or other places that offer creches if you wish to.
I remember one woman started a lunchtime gardening club in a local schoool close to her work. Told is about it on mumsnet. This was in her lunch break.
Brilliant, using a skill for the school.
Just be up front about why you would like to do this what you can commit to - eg the initial period of time.
If a lunchti thing you could offer a term, once a week, and this may or may not carry on for a time.
Some schools look for people to come in and help or read. When we thought about places to try for Dh we thought about local to where we live but, as Dh works full time, this would have been hard. Nearer work might have worked.
Anyway...
Good luck.