For the list of years:
SELECT Year(Datefield) FROM Table GROUP BY Year(Datefield)
For the months
SELECT Month(Datefield), Format(Datefield, "mmmm")
FROM Table
WHERE Year(Datefield) = Forms!Form1!Combobox1.Value
GROUP BY Month(Datefield), Format(Datefield, "mmmm")
ORDER BY Month(Datefield)...