Software testing has a lot of tools/technologies which tester should know.The most of them are really useful. But the key idea to be most appropriate to company's technical requirements.
For instance, you open a vacancy of "A" company and see something like that: "to have experience in continuous integration (TeamCity, Bamboo, Hudson)", "Mmmm, what is it? Oh, okay, I should learn about it((",-you are telling yourself.
How is it going? Yes, a lot of tools require licenses, but there's YouTube with video-views, there are a lot of tutorials to any frameworks - I recommend to read technical documentation on needed tools because it is so necessary for tester to can understand technical documentation.
I want provide a set of common tools for tester which will be really useful in your tester's work:
-Bug trackers: Jira, Redmine, Gitlab, Phabricator.
-Test Case Managers: Zephyr, TestTrail, TestLink.
-API testing tools: SoapUi, Fiddler, Postman, jMeter, Runscope, Advanced REST Client.
-Debugger: Firebug Test automation tools: Selenium, Watir
-And books: Software Testing: A Comprehensive Approach - Bill Laboon, Agile Testing: A Practical Guide for Testers and Agile Teams - Lisa Crispin, Janet Gregory, A Practitioner’s Guide to Software Test Design - Lee Copeland
But when I was looking for a job as a software tester I met the one real problem - my resume. I considered I provided all of skills that completely match with hiring managers needs but I didn't get feedback until I rewrote my resume.
It is easy to tell (and actually do): write a readable, informative, catch-eyeing, good formatting resume but I had to read a lot of literature to realize how many problems I had with my resume. I tried to combine my knowledge in the one place and now I want to share it with you.
I pretty sure if you use this advice you can get a software tester position.