Create the guest account in Active Directory, add them to any groups that you want.
Navigate to the base folder/directory that houses all the folders shared over the network.
Right click -> Properties -> Security
In "Group or User Names" make sure that the guest user, and any of their groups, aren't listed. I generally just include the Administrator group, creator owner and system.
Click Apply then Advanced. Tick "Replace permission entries on all child objects ...". This will copy the security permissions from the base folder/drive you just set to all of the folders inside the base folder/drive. If you have any custom security settings on child drives they will be overwritten.
Then on each folder you want the guest to be able to...