This is a guide that I have found to work quite well for starting players. It is a build for a LV 50 Summoning Druid. After LV 50, feel free to put skill points wherever you see fitting.
For this build, you would want to ONLY put points into the Druid's Summoning tree. (PTs are skill points.) 10 PTs.- raven (completely optional, but at lv. 20, your 5 ravens combined do about 6000 damage before they all die.) At least one PT.
15 PTs.- either Spirit wolf OR Dire wolf. I have found in my experiences that I prefer the spirit wolf, but that's me. One PT. into the other wolf.
20 PTs.- Grizzly. This will greatly pay off. Massive damage and gets a very big synergy bonus from your wolfs.
At least one PT.- oak sage. Its not that good in later game. your main Spirit will be Heart of the Wolverine (abbreviated HoW) Sink all of your extra PTs. into this.
1-20 PTs.- Any of the vines (they are ok after about Act II in nightmare mode), Spirit of the Barbs. (If playing online, just get a paladin with thorns. Its so much better.)
The best vine overall is the poisonous vine
Strength- Should be within 5 of your vitality at all times.
Vitality- Easily the most important stat for the druid. Should be as high as you can get.
Dexterity- I didn't put PTs. into Dexterity till the beginning of Act II. By then, you will want to put PTs. into it to raise your attack rating.
Energy- NO PTs. Mana raises itself with each level.
Anything boosting druid summoning skills. There are a lot of charms that will do this.