Do websites with pictures of people on the first page make the company look more "human", therefore contributing to the success of the product or service the web site tries to promote?
Short story:
I am going to start a small software consulting firm, and for starters, there will be just 3 people in it. I don't consider this to be sufficient enough to make photos and put it on a first page as a banner.
Many new companies do it with a few more employees, and for my personal opinion, it looks very good.
I don't want to place just some obligatory pictures in the web site design, since it would not be about my venture, and, therefore would be a form of lying to the customers.
I don't think it's necessary to put pictures of people on your site, especially if it's not you. If you're looking for design guidance, research several websites that are similar to what your consulting business does.
I would avoid putting those stock business folk looking photos on your site, that trend started 7-8 years ago and is played out. Whenever I see too much of that and/or excessive keyword stuffed text it makes me think "domain squatter site".
It's all about branding in the most traditional, all encompassing sense; in other words, if the photo you want to use is an integral part of the home page and site (and brand's) branding and tells the user something that you cannot otherwise convey with proper design, then perhaps there's a place for it. But as others have said, a stock photo of something generic not only doesn't tell your visitors anything specific, but it has the potential to make it clear that you couldn't find a specific message to tell. Either take the time to shoot a photo (content) that is unique to your brand, or don't include it.
I concur with the previous answers by Don and Joe. Although I would since I am designer. It's encouraging that non-designers understand and appreciate that value that design can add to a business.
Nothing screams generic and thoughtless these days more than those "trite cliche... multiethnic, posed stock photos..." as Don so eloquently and humorously puts it.
And since differentiation and positioning is the name of the game for any business regardless of size, these sorts of images do nothing to help you get "into the mind" of your client and separate you from the rest. Not only do you need a positioning statement but you need visual images that complement your unique message.
A great and timely article on branding startups was just posted on onstartups and can be found here.
I had a boutique client (4 people on staff including the two owners) this past year that had the same problem. They are IT consultants and provide server solutions for other small and medium-sized companies. They told me they had a "credibility" problem with their prospects because their previous marketing materials were not very good. They had really generic stuff with lots of these stock business and server images. So we did something a lot more "graphic" and original. They are now in love with their new look and promo materials, which have been both noted and favorably commented on by many of their prospects during sales calls.
So I have seen results in my own experience with firms with your profile. Two cautionary notes:
Finally, here are some sites to help you get started looking for the right designer (and these sites are loaded with talent):