If you already know the subject in Czech, I strongly recommend using Wikipedia to help you. Start with articles in the Czech Wikkipedia, cs.wikipedia.org .
For example, look up Cívka,
http://cs.wikipedia.org/wiki/C%C3%ADvka
At the left side of the page, click on "English." You are taken to the English article on "inductors"
http://en.wikipedia.org/wiki/Inductor
and not only learn the translation of the word, but see a long essay about inductor and inductance which brings in a lot of related vocabulary: coil, Henry, choke, hysteresis, ferrite, etc. etc.