I did tech journalism for a few years out of college. I was a reporter for some of that, and an editor for some of it.
As a reporter, I would get an assignment from my editor and start hitting the phones. I'd usually have a few stories going at once: 1-2 "breaking news" type stories that I'd be expected to get out very quickly (often that day), a "medium-term" story that might take a couple days, and a feature/series that would take a couple weeks. In tech journalism, the three major kinds of sources are the software vendors, the end users (which for my beats were companies, not individuals/consumers), and analysts. Almost all of these conversations were over the phone, often to people across the country or even on another continent.
- The software vendors were usually easy to get a hold of; these were big companies (SAP, Oracle, etc) that have PR departments whose job it is to get you in touch with someone from the company. The downside of that easy access is that those PR people also train the spokesperson (often a VP/director/etc in the relevant department) on how to stay on message, so you're not going to get anything very juicy.
- End users were often hard to get a hold of, because most people don't like talking to reporters; they're afraid that something they say could get them in trouble (with their boss, with the vendor whose software they still need to buy and negotiate a discount with, etc). This was a frustrating aspect of the job for me. It was a lot of cold-calling, leaving a message, and knowing that 90% of those I'll never hear from again. That's too bad, because these are the sources that readers (who are themselves end users) are going to most connect with. Over time, I built a collection of dependable contacts here: people who I knew would be available to talk to me, and who really knew their stuff. Even so, you can't only rely on them, or people will pick up on the fact that all of your stories quote the same few people!
- Analysts were easy to get a hold of, but you have to learn which ones you can trust, and which ones would just think everything is awesome.
To navigate it, you need to get a sense of the beat. What kind of person tends to like to talk to reporters, vs who doesn't? Who's going to have something interesting to say, vs who doesn't? I never found a magic shortcut for this; every phone call was a bit more experience.
Things are pretty different as an editor. It's a lot less writing (though still some) and hitting the phones, and more of editing (surprise surprise) and scheduling. I found it easier to get into a groove, because you could manage your pipeline better. You have your regular pool of reporters and freelancers, and once you get to know them you know how long each one will take for a given story, and how much work you'll need to put in to make it publishable. The big difference vs the writing is that you're working with the same group of people (as opposed to having to find a new source for each story), which makes it easier to predict how each phase of the story will go.
Totally different from all of that, I also did an internship at a local newspaper in college. That was a lot less phone-based, and a lot more in-person reporting. For instance, if there was a town meeting, I'd go there and report on what got said; if there was a 4-H event, I'd go there and talk to the participants; if there was an election, I'd meet the candidates in person and go to their events. I found it more fun and rewarding, but, not for nothing, those jobs tend to pay a lot less.
There's also a personality aspect: to be a reporter, you need a bit of a dogged, in-your-face attitude -- but you can't seem pushy or like a jerk. That is, people are going to try to pull the wool over your eyes or avoid the question, and you have to be able to call them out on it in a way that gets them to tell you something real, as opposed to in a way that just makes them clam up even more. It's something I never really got comfortable with, which is part of the reason why I moved from reporting to editing.
And lastly, the social aspect: journalists are awesome, funny, intelligent and skeptical people. Lunch was always a blast, and I'm still good friends with a lot of the people I met at those jobs -- it's what I miss most about it. Be prepared for sarcasm, cynicism and dark humor. Be prepared for a lot of that.