You're not really sure if you want to use Fidelity or Wells Fargo, or maybe you're just a Scott Trade type of investor? You can get a feel for some of these investment services by visiting their website and poking around without actually signing up or transferring money. Many have information pages that are open to any interested browser with tools like calculators and contribution suggestions. Take a look and you may learn that you are already savvy, or see that you have some real shortcomings and need the help of a professional.
Source: http://www.401k.fidelity.com