If you group once per month (right click on the field grou and you can chnge the look to month-year).
FOr the SUmmary it depends on your data. If you havea field per row that you need to sum:
Insert a SUmmary using that number field as a SUM reset on group footer 1.
it will be on the GF1 and show you a sum per month.
If each row is one job then insert a Summary as a Count of the Primary key of your job table reset on group 1.