Have you already been looking at www.songmeanings.net. Search for Bon Jovi and then Always. There's a similar thread over there.
I'm kind of an Always expert, so here's my personal opinion

I don't really think it's about a stalker, even though Jon has said it is.
A stalker is indeed someone who can't let go of a previous lover (or just an admired person), and keeps on writing letters, making phone calls or just following the admired one. But Jack does none of this. He just thinks about her and he knows he'll love her always, but he doesn't mean to hurt her or so. But however, it's a very strong love that will not pass by as easy...