Are you a part of Intranet project?
Are you? If you are, this might interest you. I've been doing some consultant work where I'm basically putting Intranets to the test. Basically I'm the troll telling people what are they doing right or wrong.
So his is what I've found so far on things that you might want to avoid.
Unclear intranet ownership and governance
The problem here normally resides with the the people that define the user privilegies. Normally they either have more people than they should with "admin" privileges, or they have just one person. Both are normally wrong. You should make clear choices on who takes care of what. But more importantly, the people using it should know who's in charge of what.
Designing by opinion
This is the most common mistake. The people designing the Intranet, do it by what they think is right, but they don't do any background work to support those decisions. This will bit you in the ass sooner than later.
Designing only half of the intranet
Again, a major design problem. The guys in charge of the design think:
It's a Intranet, only the company will see this and the world is not going to care about it. So I'm just going to design a couple of pages and define some guidelines and it will be ok.
It's not! If people are using something you're designing then you should make an effort to do a good job. Not just because it's your job, but because people are going to care about your product. It doesn't matter if it's 3 or 1000 users. If your work affect just one person, you should do a good job. This is a fact for everything not just design.
Taking the publisher’s perspective
The guys building the Intranet take the publisher perspective disregarding the users perspective completely. This happens not only on Intranet projects but on most big web projects.
Allowing technology to rule the design
This is a common one when it comes to Intranets. Normally Intranets aren't built from scratch. And that's ok. But the technology that you chose shouldn't dictate what can and cannot be done by your users or publishers.
I've found many more throughout my consultant experience. But these one were the ones that I found more often. I hope this helps you in the future when you have to build or work on a Intranet project.