There's many ways to achieve a glow around your text and Gimp has Alpha-to-Logo script-fu's that do a glow or neon edge. This tut is for a different kind of look to an outer edge and if it glows or not depends mainly on your blur settings, what you blur, your layer opacity settings and what colors you choose.
I have one image to this tut, numbered to go along with the operations.
Choose your font and type your text onto your image (1). Go to Layer> Transparency> Alpha to Selection in your image box. You'll now see marching ants around the edges of your text. Now click on Select> Grow> and your desired number (varies depending on font size and how much you want to glow around the text).
Add a new transparent layer. Bucket fill your desired glow color inside the marching ants on your new layer, repeat if necessary to fill in all outlined areas. You'll be left with something like (2) when the text layer is hidden. Click on Select> None. The ants should be gone.
Still with the glow layer selected, go to Filter> Blur> and this is your choice which one you want, and repeat the blur as needed. Note: Gaussian Blur will add a gray edge as in (3). Now make your text layer visible and you should see what looks similar to (4).
If you want your glow to be semi-transparent, select your glow layer and adjust the opacity until you get the desired effect (5). Merge your text layer to your glow layer if you are happy with the results. You can always blur the text layer, as in above different blurs produce different looks.
You can also add drop shadows. In example (6) I have a drop shadow in black for the text layer and then another in a really dark green for the glow layer, which isn't transparent. (6) is made up of 4 layers if you were counting. Merge these together before moving your text to their final home on your page.
Before you merge you can experiment by taking your text layer and moving it beneath your glow layer. You might not want shadows with this or wait until you merge those parts together then adding one.
You can create a unique glow by using the drop shadow tool (script-fu) but it will only be on a diagonal instead of on all sides. You select a bright color for your drop shadow in place of black or dark earthy tones. The examples are below: