I'm trying to avoid using the cluebook for MM1, but I did have some questions about character creation... is it important to have really high stats? For example, if a knight has high might and endurance, do I also need to make sure his other stats are decent also? I'm trying to get a sense for how important it is to do lots and lots of re-rolling.
Also, are there particular stats I should try to max out for my robber?
Thanks!

(edit: check the TLDR version at the bottom of this post if you're not into M&M essays :)
I haven't specifically played MM1, but the stats and their various functions remain fairly constant throughout the series. If someone knows otherwise, disregard my suggestions. :)
Anyway, stat points in the M&M series mean exponentially less as you accumulate more of them. Going from 10 Strength to 11 Strength would be much more likely to end up increasing your attack damage than would going from 105 to 106 Strength. My example is also important because, as you may or may not know, the M&M series is notorious for throwing plenty of stat boosts, temporary and permanent, at your characters, so it is not unusual to end up with stat scores in the triple digits when the game is over.
That being said, rolling for high stats in the beginning is largely a matter of pleasing the compulsive min-maxer within all of us. You'll hardly notice a difference between a Knight with 16 Strength and a Knight with 18 Strength, as your character's level and weapon have a much larger impact on the damage he's doing.
As far as the rest of the stats are concerned: Intelligence is only important for Sorcerers and Archers, Personality for Clerics and Paladins, Luck for Robbers (this I'm not positive of, and I'm fairly certain luck is helpful to all classes, just not overtly), and Might for Knights. Endurance is nice to secure a high roll for in the beginning, when the extra hit points might actually make a difference. Accuracy is nice for anyone who'll be doing any fighting, while Speed is similarly nice for your damage-doers (some people suggest giving your clerics relatively low speed so that their heals land after the damage is done, but you could also argue that this could end up getting characters killed since the cleric couldn't act fast enough.)
For your robber, go for Luck first, then Endurance, Might, Accuracy, and Speed (in that order, IMO).
TLDR Version: Rolling for high stats isn't that important since you'll get plenty of stat boosts throughout the game. Each class only has a few important stats to raise. Robbers like Luck and the rest of the physical stats.

Just make sure one of your characters has a high enough strength to bash open the container for the gold key (all gibberish now, but you'll understand later :p)
edit: nevermind, thought you were talking about MM3. me & mah sleepy eyes.

Unlike in the later games there aren't many opportunities to raise stats in MM1. Stat differences at creation will remain for nearly the whole game.
Take your time rolling for good stats, else you'll have to spend even more time for reloading.
Endurance is important for all characters, especially for classes which get only little hitpoints.
Speed is important for everyone, besides affecting who attacks first it also improves armor class. I wouldn't make the cleric the slowest character, it works better if she acts before the other party members.
Strength is important for doing melee damage, especially for knights and paladins.
Accuracy is the stat for using ranged weapons and melee accuracy, it's unknown if it also affects spell accuracy.
I think luck affects the chances to withstand enemy special attack effects like poisoning and thieving skills.
Intelligence affects the number of spell points sorcerers and archers get, it's useless for the other classes.
Charisma affects the number of spell points clerics and paladins get, it's useless for the other classes.

Thanks! This is very helpful. I think I should probably re-roll my characters to get better endurance for everyone. Which is OK because I just started, and I already have my first map made so I don't need to explore all that again.