Enrolling in a college-level certification program in Technical Writing might be time consuming and not that cheap either but it's an idea you might certainly consider. There are some excellent certificate programs offered by different universities in the United States if you are just starting out in your career.
Oklahoma State University (OSU)'s Technical Writing Program is one of the best available in the United States since its early beginnings back in 1977. The students get an BA, MA or Ph.D. degree, which are actually English degrees "with a specialization in Technical Writing."
The OSU program boasts 5 lecturers, an Assistant Director, a Visiting Assistant Professor and Coordinator, and a full Program Director and Professor of Technical Writing.
The students learn how to write technical reports, write web site content, write manuals, tutorials, and résumés, conduct field interviews. The program exposes "students to the tools and time demands they will face in the profession" Plus "in this program, students can expect to hear expert speakers and get plenty of hands-on learning."
Here are some of the B.A. level courses offered at OSU (all 3 credits):
English 3223 -- Technical Communication Criticism & Theory
English 3323 -- Technical Writing
English 4523 -- Technical Writing Internship
English 4533 -- Advanced Technical Writing
English 4543 -- Technical Editing
M.A. level courses include:
ENGL 5513 -- Introduction to Technical Communication
ENGL 5520 -- Internship in Technical Writing (6 credits)
ENGL 5593 -- Technical Style and Editing
If I were a high school graduate today looking for a college program to attend for a technical communication career, I'd definitely give the OSU program an honest thought.