We sent our dd to a nursery over a child minder. Find out what nurseries are around you and what they are like for a 6mth old. I think childminders are a bit cheaper but things like sickness, holidays and things like that were really important to us in that if a carer in a nursery was ill they would get another but with a childminder if was your responsibility and also when they went on holidays too.
There are lots of people on the site who use childminders, it just wasn't the right thing for us.
We used a nursery for dd - for the same reasons as chuffed but also because we thought it was good for her to be with other children her age. I was also a bit put off childminders when my health visitor told me that she had left her baby with one and then saw the child-minder leaving the house to go shopping without the baby . I know there are some really good childminders out there but our feeling was that at least with a nursery there are always other people around who would see if anything was being done that shouldn't - there's no-one to keep an eye on a childminder.
You also need to look at several nurseries though as some are much better than others.
You have to decide what is best for you. I get the feeling you are not in the UK, or possibly not British? (Creche rather than "nursery", baby minder rather than "childminder").
In the UK, childminders should be registered with their local authority and this in theory means they meet certain minimum standards. Lots of Mumsnetters have registered childminders who are brilliant...reliable, trustworthy, loving and imaginative. Some of us have less happy experiences of them.
Nurseries in the UK are registered and inspected by OFSTED and that again means certain minimum standards of premises, hygiene, staffing levels etc.
Even so, some are "better" than others.
I have two children who have been in or are in daycare and for us, a good nursery has been the perfect solution. But if we had been able to find a really good childminder, my personal view is that until the age of about 18 months, one to one care probably suits most babies better.
Check out what is available to you locally, messy. That is going to be a major factor in your decision. You can't "choose" a childminder if none of the good ones locally have a vacancy for the next six months...
Good luck with your decision.