In Diablo 2, how should I use the bonus points at time of level up for my Paladin? I haven't been putting much into mana since I usually use an active skill for defense or attack. I stick with using my weapon instead of using his magic skills as well. My health gets depleted rather quickly so I don't know if it's an armor/resistance thing, or if I'm not putting the right points where they need to go.
This depends highly on what you want your paladin to do in the late game.
In almost all cases, you want to hit the 75% block after holy shield (max block) by putting enough dex to get to that point.
For smiters and hammerdins, you'll need the minimum strength requirement to wear all the gear you plan to wear. Any points left over should be dumped into vitality (though its arguable for a poorly equipped hammerdin to get some energy).
If you plan to go melee oriented, such as a zealer or charger, you'll want some strength instead of all vitality (its a balancing act) for more damage.
For both smiters and zealers, it helps a lot if you can find yourself a cheap wand has charges of life tap). Putting it on bosses and large groups greatly increases survivability. You can try searching shops for one pretty easily (I think on nightmare but its been a while).
I haven't played D2 in ages, but when I leveled my Paladin, if I didn't have a piece of gear I wanted to use, I would always put 2 points into Strength and 2 into Vitality and 1 into Energy.
I relied on my auras (like Spikes and Might) and Zeal to do most of my damage. This worked great until I came across a lightning enchanted boss. Hitting those guys rapidly caused more harm than good! Yikes!
If you are playing online then you should level-up ASAP. Levels 1-15 in Tristram, lvl 15-25 in the Tombs(end of Act 2), 25-45 normal Baalruns, at level 45 you go to NM, get to act 5 asap, level up till 75ish on NM baalruns, then go to Hell and repeat Baalruns till you have a decent level and somewhat of a decent gear.
Concerning stat points: enough
But since patch
So try to achieve max block(75%), enough