In combat, Bears typically use weapons that scale damage with Strength, like the axe and sword which allow the Bear to deal melee damage, and sickle which allows the Bear to be tankier. Bears generally use runes that scale damage with Strength, like Charge for stun and moving close up for melee attacks, Slash for damage and Harvest Life for healing. Bears, however, are not obligated to use these runes, as every rune offers its own functions, pros and cons and opportunities for better builds. You can consult the Advanced Guide to aid you in your rune and stat choice.
Bears generally fall into two categories:
Tanks, powerful supports with somewhat low damage but extremely high health and armor for prolonged attack without much reliance on healers.
High damage, single-target invaluable assets that greatly increase overall dpt.
Both categories have several subcategories.
For more detail on rune and stat choice and specific builds, consult the Advanced Guide.