Originally Posted by Hotrocket

The original image needs to be at least 200 dpi, some say 300 but I've found 200 works just as well for apparel printing.

The original image needs to be created at the 200 or 300 dpi level..you can't just take a 72 dpi image and "add" dpi to it.

You have to consider the actual size of the art..if its a typical website header image size it will print out at what might be a very tiny 2 inch by 6 inch image.

As was said above you really want a logo to be created in vector format so you CAN enlarge or reduce the image w/o any loss in quality.

Whatever vendor you finally use I would strongly suggest ordering a sample so you can check the final image quality, your logo has a glow around the halo and the detail in the wings that may be difficult to reproduce as designed.
You may also want to adjust colors, such as the blue outline on the text so it pops out better against a black background. Remember that the color you see on the screen most likely will not be the same tone when printed. You also have white against a black edge that sometimes creates an issue when printing white on black apparel, depending on the printing methods.