Praat is a multifunctional tool for speech analysis and synthesis. You can use it for transcriptions, signal manipulations (e.g. editing, altering stimuli duration or pitch manipulations), recognition experiments (e.g., yes-no decisions, but no latencies), acoustic-phonetic measurements. It produces nice spectrogram- and other plots. Praat comes with an implemented scripting language which allows automatized processing of stimuli.
However, Praat’s handling is absolutely non-intuitive for windows users and/or no-programmers and the massive manual is not too helpful for beginners. Thus, a brief introduction by a colleague will save a lot of time and effort.
(If you want to use it for annotations only, ELAN may be the better option)