a guide on builds:
http://forum.melee.org/guides/(guide)-toffi's-cavalry-guide-(big-update)/
guide on tactics:
http://forum.melee.org/guides/(guide)-son-of-odin's-cav-guide-(lancer)/
My somewhat unusual playstyle on my cav consists of using heavy armour, a heavy horse and a lance or light lance with a minimal riding build. I have 24/15 and going for 27/15 at level 32. Riding is overrated, this build kills infantry like a beast. I don't ride around full speed hit and running unsuspecting people, I ride around melee fights actively bumping, stabbing and distracting people to make my team win the melee. I play it like it's some sort of armoured infantry support and it works pretty well. I just have a playstyle that fits with this build, but you should definitely give it a try on a skip the fun.
Also, learn to stab over the left side of your horse, people get caught of guard by that a lot.
Thats not unusual, its a str cav build : ) was one myself for the longest time, but changed that since i like high athl.
the light horses got especially popular after the upkeep implementation, and the high speed approaches with light horses were needed after the lance nerf and bump nerf, as your HL needs speed bonus to kill, and your horse needs speed to not get stopped by one man.
and arrows. you wanna move fast. 1 shot kill arrows everywhere ^^
I personally would not suggest going "pure" lancer cavalry (aka no athletics, or no IF, maxing out riding and PS). But if you do go that route, keep in mind that your WPF does affect your couching damage (as well as power strike).
I would suggest these builds as polearm only lancer (no shield).
Either go 24/15, 21/18, or 18/21 depending on what horse you want to ride.
I'd suggest 24/15 riding a destrier or war horse (if you can afford it and use a regular lance). I wouldn't use a couch only lance without a shield (I'd only use a great lance, jousting and practice lance are obviously not as good, so why use em).
24/15:
Strength: 24
Agility: 15
Hit points: 59
Converted: 8
Power Strike: 8
Athletics: 5
Riding: 5
Weapon Master: 5
Polearm: 148
You could give up some WPF in polearms for some IF, but I'd prefer to have higher WPF than a little more HP
21/18:
Strength: 21
Agility: 18
Hit points: 56
Converted: 8
Power Strike: 7
Athletics: 6
Riding: 6
Weapon Master: 4
Polearm: 139
18/21
Strength: 18
Agility: 21
Hit points: 53
Converted: 8
Power Strike: 6
Athletics: 7
Riding: 7
Weapon Master: 3
Polearm: 132