The PostScript picture should contain a well formed bounding box comment indicating where on the paper the figure appears if it is printed, so LaTeX can calculate how to scale and move it to fit where you want it. Many programs produce figures with wrong bounding boxes. Ghostview shows the coordinates of the cursor in the upper left corner, it makes it easy to measure bounding boxes. Particularly useful if the figure contains a white background that otherwise will overwrite some text. Rotate the figure 45 degrees anticlockwise.
Height is how much it goes above the baseline, depth how much it goes below.
Epsfig rotates around the lower left corner, so if you rotate by -90 degrees the entire figure ends up below the baseline, i.e. the height is zero but it has a depth. Measure the dimension with bbox. This will produce lines with a little more extra spacing between words, and you should therefore increase TeX's tolerance for such lines. Most of what this page contains come from one of the following sources. You can look there yourself for solutions to similar problems.