Manual
1.Intro
First things first, DSpellCheck was started as the project which should have eventually become decent spell-checking plugin for great text and code editor Notepad++. Was that goal reached or not is left for you to decide in the end, but anyway almost all stuff that I wanted to include in this plugin was eventually included, so I feel pretty content about it. Why spell-checking for Notepad++ is useful? That question arises all the time and the people who asking it of course encouraging to use different programs for spell-checking but I believe that first point is that it's totally depends on user point of view (I guess not everyone is very eager to use programs such as Microsoft Office, OpenOffice or LibreOffice for editing simple txt files). But there is more to that of course, I guess even if not everyone uses Notepad++ as C++ editor but at least for HTML, TeX, PHP, and other languages where you do not use some kind of IDE every time, you can consider Notepad++ as one of the best editors, and of course typed text in such files still needs to be checked. I mean in TeX is almost everything is text but still there are some keyword which should be skipped ('cause they are not English words all the time and while doing spell-checking for other language it is even more important), in C++ you probably want to check only string constants and comments. And basically all of stuff like that is the possibility I've tried to put inside this plugin, which I believe makes it pretty much useful for majority of Notepad++ users.
All the hotkeys described here could be change through standard Notepad++ means.
Plugin works like most of spell-checking plugins these days, it just underlines every word which misspelled or seems to be misspelled from speller point of view. When you see that the word is being underlined you can put your mouse cursor over this word and then little red box will appear under it, which you can click and context menu with some suggestions for misspelled word plus two standard options (Add to user dictionary, Ignore for Current Session):
If visibility of this box bothers you, don't worry it will disappear almost on every action that you will be doing except moving mouse cursor. Actually there is an option to make process of getting this menu differently (See link).
By default plugin either doesn't have any dictionaries at all or have only English (Great Britain) dictionary installed. The easiest way to install more dictionaries is to go to Plugins->DSpellCheck->Change Current Language (or just press Alt+D) then select download dictionaries, choose dictionaries from list you want to download, press button "Download Selected", and then more dictionaries will appear in the list of "Change Current Language" menu which you can select and of course use.