here is your blinking tutorial: 1) open animation palette. 2) add new frame by duplicating the current frame. 3) turn off the text layer that is visable. (the text you want to blink) The text will now be blinking in a 2 frame animation. 4) set the frame rate. 5) save your animated gif by selecting file>save for web.
Open the animation window, make 2 frames, and make the layer of text be displayed on one and not on the other one. Then save as .gif. Easy peasy.