Networks

I am looking for software that will allow me to monitor a smallish (les than 30 PC's) network from my desktop. I am looking for the ability ot see what specific desktop PC is utilizing how much bandwidth, or the amount of traffic a computer is generating plus the usual monitoring tools of bandwidth utilization. Connectivity status and more. I will admit that I just graduated from school and am somewhat new to actual real world implementation so ease of use is essential. Any suggestions out there?