Culture counts when looking for a job. Good cultural fit and positive work environment are usually critical factors in whether someone will be happy in a job, happy enough to put in time and energy, and not suffer stress that can lead to personal and health problems.
It's a good idea to come up with your own "Must Have List" of the five or six things you must have in order to be most productive and satisfied with a job. These are 1) the actual work you'll do; 2) your role in the company; 3) the impact your work will have; 4) the physical environment you'll work/commute in; 5) the company culture; and 6) total compensation. Once you have that list, you can assess every job according to those criteria. "Must Haves" are exactly that - the minimum conditions you must have. Over time, I observe that people narrow the list down to a top 2 or 3 items - and usually, culture is right at the top of that list.
So how do you find out what a culture is like? There are different cultures within industries, and culture depends in large part on the top leadership. Reading about a company can give you clues as to what it's like. Google the CEO and COO names to see what the press says about them.
Likewise, job postings and descriptions give clues about culture. When a job description uses the word "team," it's likely they value people working together. A company that actually states its values has a greater likelihood of having done the internal work to come up with those values. (This is not guaranteed, however; Enron had a values statement...) If a posting says "must work well under pressure," chances are it's a very harried place where you can expect to put in a lot of overtime.
When you apply for a job at a company that seems to meet your minimum culture requirements, refer to your values in your cover letter. That way, the reviewer knows right up front who you are and can make an initial assessment about the likelihood of cultural fit.
In an interview, ask directly about the culture. "What's the culture like here?" is a great way to find out. If they can't answer clearly, chances are they haven't thought about it very much and it will be more of a "dog eat dog" environment. If there is a values statement, ask how it was developed.
If it turns out that you are not finding companies in your field that meet your requirements, maybe it's time to broaden your search outside your industry. There are many tech jobs in other industries, including health care which is still growing.
Finally, trust your gut! If it doesn't feel like the company has a culture you will thrive in, it probably won't. If you're desperate for a job, accept it knowing that you are making a compromise - and keep looking for a job that's a better fit for you.