Once you build a barracks, you should immediately build infantry and use them to uncover the map and find your opponents base. Send your infantry to the corners of the map and a few down the center. Build a few and place them around your base to guard against your opponent's infantry who will most likely do the same. Remember, the first few minutes of the game is critical. Your first objective should be to find and uncover your opponents base and the surrounding areas.
Dogs are great units to use as scouts, and are cheap to produce.
So if you lose a few it won't matter so much. And they are very fast on the move. They can cover a lot of ground in a short time. Just keep in mind Red Alert2 was designed for fast and furious gameplay. But you will run into times when games can go the long route.