Create a table of two cells.
Put one flag image in the left hand cell and align it to the left. In the other cell put your image in but this time aligned to the right.
To place them at the top of each cell do this:
At the bottom replace top with bottom and in the middle replace top with center.
While your're setting it up keep your border switched on but once you're happy with it switch it off. ie border="2" change to border="0". Don't leave the '0' out otherwise you'll get a thin border.
For a logo in between the two flags then start with a 3 cell table instead and simply put your logo image in the middle one.