What you are reporting is normal and expected. The fan speed will range from a low of 2000 rpm to about 6200 rpm dependent upon the heat being generated in the MBP. You have no cause for alarm. Understand that the aluminum case is part of the heat dissipation system and will become warm which is good.
I personally do not think that any fan control software is needed. I have faith in the Apple engineers that designed the MBP cooling system.
Heat within the MBP will range from the high 30's° c to about 105° c when thermal shutdown will occur. When performing lightweight activity such as word processing and Internet browsing, one may expect temperatures in the 40* - 50* c range. If one is engaged in games, using Skype or other heavy weight applications, temperatures in the 90* c range are common. Fan speeds naturally will increase in those conditions.
This is an image of my MBP iStat pro as I write this response:

Ciao.