Job descriptions are an interesting phenomenon. Overwhelmingly, they all look alike. After a few hours of searching, the positions all start to blur together. If you had a nickel for every time you've read the phrases "communication skills," "interpersonal skills," and "attention to detail," you could probably call off your job hunt all together. It should be obvious by now that nobody would want to hire an employee who couldn't communicate, wasn't easy to get along with, and didn't pay attention to details.
What's a job seeker to do? You could wait around for employers to catch on and stop dragging these old cliches out every time a position comes open, but it's unlikely that is ever going to happen. That only leaves the option of learning to read between the lines and decode the unhelpful verbiage of generic job descriptions.
It's typically helpful to read the descriptions "backwards." Job descriptions tend to bury the lede, so you can save yourself a lot of time trying to figure out if a job is a good fit for you by saving the details until after you've read the important bits. The "qualifications" and "minimum requirements" sections are usually found at the end, yet are ironically where 90% of the pertinent information is found. Here you'll find out about the minimum years of experience required, any programs or software you'll need to be familiar with, and any specific experience that the employer is looking for. Often the requirements will tell you more about the position than the generic position overview.
The years of experience required can be very telling in and of itself. Most companies will not post this number as a range, but rather in a minimum and up format. This has a lot to do with age discrimination laws, but you can use it to your advantage to decode a possible salary range. For example, 3+ years required generally indicates that they'd like someone earlier in their career (and therefore less expensive), but not someone who is just starting out. If the role is higher level and the employer is open to paying for a more seasoned employee, this number will usually be more in the neighborhood of 5+ or 7+. The 1+ years required level essentially indicates that they're open to those with minimal experience, but that the budget for the role is probably suited for someone very near entry-level. This can save you some time if you are a veteran in the workforce and have a salary to match. Even though someone with 10 years of experience technically qualifies for a role that calls for 3+, chances are good that they will be overqualified and out of the budget.
While you're down there at the bottom of the description, reading all of the helpful information, check out the education requirements as well. Most employers are pretty rigid about this. If all of the above check out, then you can assume it's safe to invest time reading the more banal functions of the job. Pay attention to any repeated phrases from the qualifications/requirements that might be in the job duties summary. If something is mentioned in more than one field, it's a likely indicator that the hiring manager's emphasis will be there (and therefore something you might want to focus on in your cover letter/resume).
You can pretty safely skim any bullets that refer back to the actual job title. For example, if you're looking for a role as a Human Resources Manager, bullets that say thing like, "administer Human Resources programs" aren't going to be of any use to you, considering that ought to be something that goes without saying. Conversely, any words that aren't typically associated with the position you're looking for will indicate unique functions of this role. This is where you're going to find out what makes this role different from every other position you've seen. If there aren't any, then it's probably safe to assume that the role is pretty typical. That might not be a bad thing, depending on what you're looking for, but it's certainly something you want to know upfront.
Learning to efficiently read the less-than-great job descriptions that flood job boards and social networking sites will save you a ton of time and energy. There is no sense going after positions that won't be a good fit for you. Some tend to take the shotgun approach and apply to everything that looks remotely close, but this can actually be a detriment to you in the long-run and will probably only cost you time and energy. Your best bet is to get some practice reading JDs. You'll learn to figure out that what they actually mean by "fundamental knowledge of Microsoft Office" is closer to "ability to print and edit documents" than "extensive knowledge of Microsoft Excel pivot tables."