What is the best way to set boundaries between my mother in law and me when it comes to raising the kids?

I am having some issues with my husbands mom in how she likes to take control in raising our kids. It's like she is trying to raise our kids for us instead of giving us the chance to raise them ourselves and ask for help if we need it. She is always offering her advice, which is fine because we are young and don't know everything when it comes to raising kids, but we would like to be the ones to ASK for the advice before it is given to us. And she tells us when she wants to watch the kids, not giving us the chance to ask if she is available to watch them for us. I always thought it was the parents who asked the grandparents to watch the kids or to ask for help first, not the other way around. My husband is close to his mom because he works for her at his parents business. So he always is around her. I know she is a big influence on him but it's like he is afraid to stand up to her and take a stand. I'm sure he is afraid he'll hurt his parents or make them mad but I honestly think that if nothing gets done with this issue that it'll end up where everyone gets sad/mad at everyone else. I don't want that to happen. I want them to be a part of my kids lives - but I want us to be able to raise them and have a say in where they go, not having them tell me what is happening with them (sorry if that is confusing). It just seems she is trying to intervene in our lives and push her techniques on raising kids onto my husband and me. I'm taking everything into perspective and seeing both sides of it but I still think that since we made the decision to have a family we need to join together and raise them together, not having his mom always come and rescue us (when we don't need rescuing). It's like she is a safety net to him and he feels he can always rely on her when something goes wrong or when we take the kids out he feels they need to come with us in case the kids start getting fussy or throwing a tantrum. I think we can deal with those situations as they happen. Kids will be kids, I know that and yes kids cry and fuss - but as parents it's our job to resolve those problems as they happen, right? Not having his mom step in and take over. I just feel that we need to set boundaries so we know where everyone stands and everyone is happy in the end. thanks for the advice :)