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I am doing an upgrade of network cabling in an office building (basically the grunt work). The network guy told me to run cat6 to all locations. I am fairly new to the data industry. Any suggestions as to Cat6 or cat6a, or anything special I should know?

I understand the termination can take longer to do

Make very certain that you don't bend the cable sharply. Cat6 is extremely sensitive to bending radius. Most times even trying to straighten it out after it's been bent still results in the cable failing.

Watch out for any stub UP that you have to pull. If the whip that you pull gets stored in a coil waiting for the end of the job, just the cable hanging down over the end of the conduit can mess it up.

Any cable that fails the tests at the end of the job can't be fixed and will need to be replaced...usually by you at no extra cost. Since we're all working at razor thin margins these days, also be careful about other trades stepping on or yanking your cables once you've got them installed.

There's a lot you should know. If you're not even sure what the questions are, you probably shouldn't be installing a data network.
I'm not trying to be insulting, but answering your question completely would be like trying to put you through apprenticeship. We're happy to help, but your question is huge.

Now hang on a minute, Greg.
This guy could be a pretty darned good electrician that is looking to branch out into new areas of work.
The only REAL difference between a Cat5e cable and Cat6 is the internal "+" filler seperating the twisted pairs.
He is running these cables, he was asking for advice on running them.
I don't think he is asking how to hook up the patch panel.

I did an office with a couple hundred outlets. I pulled two spare cables and used them both. The spare cables saved hours of work and we were able to get the replacements in place and terminated so it didn't hold up testing. As careful as you might be, something or someone can snag a cable.

They are as hard to terminate as cat5 and take about as long. I give that job to apprentices. They love it and talk about doing it for a living - for the first day. If they mess up, no one gets hurt and it only takes a few minutes to fix.

We leave a coil of about 20 feet above each outlet. It's nice to be able to move the outlet when the desk is relocated.

We had specs to leave a 20 foot coil over the rack, but that was a disaster with that many data cables and almost as many telephone cables. I prefer panduit or a cable-way to hide a couple extra feet so that end can be re-terminated, too.

There is a school of thought that says you never coil CATx. You are supposed to make lazy "S"s. I am not sure I have ever seen proof, it is more of a (choke) theory thing.

If so, many schools, companies, universities and districts, plus their various installers, have done it wrong for the past 20 years. I've never seen any Cat5/5e/6 contained using anything but coiling.

4/0 feeder, on the other hand...

I agree. I said I have never seen any proof. It was just a warning of things you might hear. When I was doing TDR training in my office I had a couple hundred foot spool of IBM type 1 cable hooked up and it worked fine (just trying to get some length out there). I also had "baseband" cables coiled on top of fluorescent troffers, tywrapped to the feeder going to the elevator and every other thing I had heard legends about. The stuff just ran.
OTOH I could show you a kink in a CAT 5, every connector and a nail through it, even one that didn't pierce any pair insulation, showed up like a sore thumb. An overhand knot is pretty ugly too.
If you were sloppy doing your terminations it was almost as bad as the nail.
We were still going pretty slow in those days so the LANs still ran fine with all of these things but these days with gigabit over copper you may not do as well. The effect will usually just be the network slowing down and everything may still "work" but your LAN administrator will be tracking it down eventually if they are earning their pay.

The prohibition against coiling the cable comes from the world of radio and TV. Broadcast signals can end up causing ghosting if the cables are coiled up.
You can coil Cat6 to your heart's content, just don't kink it or bend it too sharply.

BTW, lots of times Cat6 gets specified because that's "the IN thing to have". If the network can't handle those speeds, the full capabilities of Cat 6 are never touched.