Our carpet will be installed soon, so we invested in several rolls of the sticky, clear carpet-protector film. HD sells 50-ft rolls for about $13 each. It's exciting to finally be this close to move-in, isn't it?! :-)

If you have any carpet scraps left over, use them to make walking paths through the rooms. Put them upside down on the carpet.

One other thought - - builders in our area often provide "booties" (the blue type similar to what they use in hospitals). Once carpet is in, everyone who enters the house is required to either put booties over their shoes or else take off their shoes. We bought a bunch of non-slip, extra-large (good over work boots) booties on eBay for a very reasonable price, and we'll be using them, in combination with the sticky film I mentioned earlier.

Probably too late, but this place also has the sticky carpet protector film to protect new carper as well as some sticky carpet protector mats to take dirt off of shoes as you walk in the home. this avouds some of the nuisance of takign booties off and on.

Here is a link that might be useful: protecting new carpet