Does the amount of villiagers affect the speed a building is built (or something else is built for that matter) like it would in real life, or is it like the villiage garden in which nothing increases or decreases the speed in which food is gained.

yup the more villagers threre are building , the quicker a buliding is done

Considering the amount of transportation that's needed, having builders who like running may help too.
Speaking of which, in my current game there's a woman who's a running builder. She rushes up to the quarry, grabs a big boulder and zips back to the building site past her slower male colleagues. So much for "the weaker sex"...

It's the same with the other specialisms, too, apart perhaps from doctors (but see below). The more farmers you have, the more food you get (assuming the supply doesn't run out). The more scientists you have the faster you gain tech points. However, this also depends on the scientists' skill levels, so a couple of Master Scientists will earn more points than four at Trainee level. As has been said, the more builders you have working on a project, the faster it will be completed. The more parents you have, the more babies.

I suppose you could also say that the more doctors you have, the faster villagers will be healed. It is sometimes fun to watch two or three doctors rushing to cure one sick villager; those who get there too late will stand around looking helpless for a moment before deciding to wander off to do other things (like their laundry).

A lot of the skill element in the game is deciding how many villagers should be allocated to each task, and in swapping them around at the right time as tasks are completed.

Omgoodnees yes!

Yes, the more the merrier. The first few of my tribes I couldn't sustain because I was spreading them too thin. So I decided to have the tribe work on one task at a time. Currently, my tribe is doing extremely well.

When the crops are ready for harvest everyone joins in (I reward them with a group swim), they raze a building together and research together.

Since my tribe is growing I have begun to leave half researching and the other half doing the other task at hand.

It appears things are going much faster, my food supply is well over 2,000 at all times.

I love my little people.