Do you want to automate it? Sorting manually is easy enough, select all the cells you want to sort, right click, 'Sort range...', pick your first sort column and 'add another sort column'. For some reason selecting the whole columns at the top doesn't allow you to 'sort range'. You have to select the cells, which could still be the whole column.
If you want to get more clever than this there may be something in the script gallery that can help. Found one that sorts form responses onto different sheets depending on the answer.