Go ahead and open up photoshop, and follow along step by step. :)
Step 1. Open up the animations window.

Step 2. Set up a black background layer and white forefront layer.

Step 3. Create a new frame on the animations window.

Step 4. While the second frame is selected, select the text layer and uncheck "Propogate with Frame 1".

Step 5. Change the opacity of text layer to 0% (with the second frame still selected).

Step 6. Click the tweening button, and insert 10 frames between.


Step 7. It's ready! To save the file so it animates, go to File > Save for Web and Devices
Step 8. Save the image!

Your end result should look like this:

On your own tips:
1. Try use as little color as possible! The GIF format limits to 256 colors, so it will turn pinkish red into red etc.
2. The more frames inbetween, the smoother the animation will be. Play around with what looks best!