go to a bright star, way easier, you put it there in the center of the FOV then you can hold the ccd by hand and move in and out you will see if you have enough travel in because as the star becomes focused it gets smaller and smaller, and on the other side it gets bigger. if it gets smaller and smaller and doesn't get bigger again, you havn't got enough infocus.
If your looking to auto guide you have a mount that can already track, so that makes it alot easier.
Trying to focus on something in the daylight hours means nothing really as its not at infinity, the focus is at a different point.
Even when looking towards the moon Vs the stars... its a different focal point!
hope that helps and good luck
Brendan
PS, if your using a webcam at focal point, i think that you might have to remove the lense of the camera, as it changes things quite a bit, look up the Philips toucam and the modification to get it opperational at prime focus that should get you kicking. if not look at getting a second hand Meade DSI or orion star shoot autoguider, thats the best option if you are wanting to do DSO guided photography!