I have been on this board for over a year and haven't seen a guide regarding flashme (softmod). NO ONE softmods a DS since the advent of passme/flashcarts. Those that do usually end up with a brick. Flashcarts are easier and more reliable.
Guide on which? (flashme or flashcart) I just said that I haven't seen a guide on Flashme on this website in the year I've been on this board because NO ONE (with any sense) softmods a DS. Go out and Google "flashme" If you're asking for a guide on flashcarts, there are several, since this question is asked several times a week.
Yes. Yes it is. And as dailun has said this topic has been covered many times. Use the search function or look down the page.