Building my most deadly build:
Illiterate+Asthmatic+Any other 3 points perk
Fleet-Footed+Fast Learner+
maybe Optimist for perks
Take 2 points from strength, dump everything else into Intelligence.
Playing my most deadly build:
Find backpack quickly, collect rocks and MP3 players/batteries for mp3 players/marijuana/booze (booze only if nothing better can be found). Play mp3s/drink booze to keep up happiness right quick, and throw rocks at zombie.
Find combat knife or hatchet, or craft spear. Alternate between trapping zombies in windows so as to stab them with the cutting weapon (get them to chase you, run through doorway, close door and dance in front of nearby window), and running around in the open pegging them with rocks. Once you get a bit better at throwing you can eventually upgrade to throwing spears, but they run out too quick before killing much at lower skill levels. Remember that rocks work better against skeletons than knives, since they are nearly immune to blunt damage.
I usually get around 200-300 kills with this build. Have only lost it to bugs and rampant stupidity like running over landmines. Swapping out Optimist for Pain Resistant might not be a bad idea if you're not so good at avoiding getting hit. Make sure to collect every first aid/bandage item you come across as well.