There are different ways to do that. If you have redpower, just use it's timers. Picture 3 has an example schematics. Timer of the left is "long" one (58 seconds in our example), timer on the right is "short" (2 seconds).
Do never use RP-Timers for something critical like Reactortiming! It will explode right after Chunkload!!!
Thingie on the far right is just a "or" gate that can be replaced with one redstone wire. It is needed because redpower wire does not go "into" blocks. I learned it hard way - it was only time reactor blew in my face without me intending it:(
RP-Wires are Sources of second-degree Redstone for anything around them, and additionally in case of uninsulated Redwire, also Sources of first-degree Redstone to the Block, where they sit upon. And RP-Logicgates are sources of first-degree Redstone to all the Outputsides.
Or you can make timer from just Industrialcraft compenents. And it will look very cool.
Thank you for giving me the Idea to use IC²-Electricity for Logic. That Batboxthingy of your other Tutorial, is the first small and relyable Timer i ever saw. And the only other relyable Timer is the RP-Computer (which is expensive and complex).