I don't know about you, but I hate updating my resume; and it only gets worse when I have to rewrite the stupid thing, for whatever reason. But over the years I have learned a few tips/tricks to make it less painful, and more effective.
TIP 1: Write a page not a novel
Most people who have to review resumes, have a lot of resumes on their desk and they usually have other duties than to hire people; thus they often only read/skim the first page, and judge based on that whether to give the applicant a shot.
TIP 2: Keep it very relevant & recent
I big misconception is that you have to include every job you have ever worked or at least every relevant job you have ever worked. Not true, as interesting as your days may have been as a fry cook, your employer will skip over every irrelevant job. Keeping things recent is important too, even if you were good at your job 10 years ago, it will give you little credit now.
A good resume generally has between 2-5 relevant jobs, where the majority of them are fairly recent, while the minority may reflect great accomplishments that are also relevant. (e.g. a large successful project)
TIP 3: No paper or plastic
Turning in a physical resume as a developer can be a bad idea. While in many industries it is ok, as a developer it can make you seem "outdated" or "old-fashon," which is usually not good. While this isn't a common problem with employers, better safe than sorry.
I personally recommend these formats because most computers can view them properly:
rtf, pdf, odt
TIP 4: Keep it online
Keeping your resume online has 2 benefits:
1) Easy to access
2) Easy to change
I have used sites dedicated to resumes in the past, but I found the best results in a slightly unusual place. Wrttn.in is a site typically used to write down various text in Textile/Markdown markup. Their minimalist approach to design is very nice, and perfect for resumes.
As an added benefit, it is harder for a person to tell exactly "when" the first page ends, so you have a little leeway with your content length.
TIP 5: Details not explanations
While some things may require explaining, leave that for the interview. All the employer really wants to know is what qualifies you for the position. While I could go into detail, this would be something better shown than described.
TIP 6: The left hook
While this tip is optional, it can be very helpful. By adding a "left hook" to your resume, you can make you resume go from their fourth choice to their first choice. The left hook is usually an astonishing achievement, something to catch the reader off guard without scaring them away.
(e.g. I created this million dollar product OR I ran this company)
In some cases, where the company is very relaxed, the hook doesn't need to even be relevant.
(e.g. I once wrestled a bear and won OR I have sky-dived 352 times in my life)
Remember: Not everyone has a left hook
TIP 7: Law & Order
While I personally hate the show, those 2 words are key for any resume. Following these tips as if they were "laws" and keeping your resume from looking like just a lot of words, will generally get your resume at least noticed.