I am by no means an Illustrator expert, but I am learning things all the time. The other day I discovered, by mistake, how to add some detail to plain fonts.
Step 1: Write your text and give it an outline stroke in the same colour as the text fill.
Step 2: Go to type > Create Outlines
Step 3: Go to Object > Expand
Step 4: Click OK (if fill and stroke are ticked)
Step 5: Select the white stroke colour
Step 6: If you want to you can adjust the size of the stroke to give a different effect (Above =1pt, below =0.5pt)
Have some fun with the various stroke sizes and fonts (click on image to enlarge):
And play around with colours: