You might check these links, many answers and suggestions talked about a lot.
http://www.chiefdelphi.com/forums/sh...ad.php?t=34772
http://www.chiefdelphi.com/forums/sh...ad.php?t=37693
http://www.chiefdelphi.com/forums/sh...ad.php?t=37216
http://www.chiefdelphi.com/forums/sh...ad.php?t=35916
http://www.chiefdelphi.com/forums/sh...ad.php?t=33457
http://www.chiefdelphi.com/forums/sh...ad.php?t=34430
And those are just on the first page in the "Scouting" forum. Check them out.
Scouting is for anything and everything and I feel it is an extremely important part of doing well during matches. It's for watching team's consistency, their strategy of play, to size up your own strategy, to know what a team can or can't do, regardless of what they tell you in the pits, to strategize with your partners and against your opponents, etc.
Ours is done on paper, we have tried other methods, but always come back to that. We do pit scouting (to get the technical aspects of every team's robot), and we do match scouting (to get the play aspects of a team and their robot). Match scouting sheets change each year to fit the game. Pit scouting is done on Thursday. Match scouting goes all day Friday and Saturday until elims. Depending on what type of scouting you do and how detailed you get, you can have one scout per robot on the field during any match.
Our scouting is effective. It is important to know other team's capabilities, strategy, and consistency. I feel it is not as effective to only know straight statistics on team's performances, as it is to know the things I mention in the first sentence. Standings are not as important because they could just be unlucky with partners, but have a very well performing robot of their own.
The key is, if you're in alliance picking, to choose a robot that is COMPATIBLE to your own, one that maybe does something you can't do. So you would figure out what that is, and you might scout those teams closer. Rankings, and objects scored won't tell you that kind of info... (not saying we don't use that info, but it's not always the highest priority info). I think most teams scout every other team, and maybe narrow it down the second day.
We never give up scouting. No matter what our standing is going into Saturday, you never know what will happen, and if a team chooses you, you could be a hero for having all kinds of detailed info on your opponents. Plus, it gets the students (and adults) familiar with other teams. You might just see those robots again someday.