We're currently hiring at my place of employment, and as the lead (read: only) developer, I'm left to sort out who we should hire from a technical point of view. After reading through a pile of resumes, I'm beginning to notice a few common 'trends'.
Now, I won't claim to be a definitive guide, but just a few tips from my experience.

1. Read the job carefully
   We're after someone who is serious about working as part of our team, if you can't be bothered at least reading the job advert, then you've failed the first test. If the job is titled "PHP DEVELOPER", and you can't code a single line of PHP, then perhaps you should keep looking.
   
   
2. Elaborate on your skills!
   This relates a little to the above point. As the people hiring, we're always really interested in any other useful skills you may bring to the company, but we are primarily interested in the skills relating to the job we have on offer. If we're looking for a PHP developer, please, please, spend some time telling us what you have done and provide some examples. Sure you may know and have 50 examples of asp.net sites, which is cool - but we don't want to read 3 pages about skills we aren't really that interested in.
   
   The tip here is, keep to the subject!
   
   
3. Personal Attributes
   Fitting in with the existing company is very important, we want to make sure you can get along with everyone and enjoy your time at the office. If you enjoy certain activities, put them down! We are only human, so showing us a bit of your fun side never hurts, although be careful not to put down controversial activities.
   
   A common theme I'm seeing is a giant list of 'attributes', ie "i work well in teams, I have a passion for xxx, etc.
   Now, I want to know about you, but if you give me a list of 40 bullet points, all of which obviously lifted from some Year 11 school "how to write resumes" class, it sets the B.S. meter off. I'd rather that you be honest, and write a paragraph about yourself and your approach to people/work.
   
   
4. Cover letters are great
   Cover letters only need to be a few paragraphs, but it proves that you have read the job properly, and have put some effort in. There are too many desperate job hunters who fire off 100's of resumes a day, all with no cover letter, or something generic. If someone has taken the time to write a personal cover letter, I will always read it.
   
   
5. Examples are twice as important.
   So, you have a nice shiney degree (or maybe you don't)... the harsh truth is, for many I.T. jobs your degree means absolutely nothing compared to examples of work. While there are fields where this won't be true, in the I.T. industry it's awfully common to be unqualified yet "excel" in your field. Make sure you list and elaborate on any real life work you have done relating to the job description, it will mean a lot to the reader.