You can do no better than follow
this link. It's obviously dated, but it explains better than any document out there the doctrinal distinctives which separated the Baptist denomination from the others of the day.
Since then, there have been some drastic changes. Particularly here in the good ol' US of A. But lately there has been a return to the doctrines of 1689 within our largest Baptist denomination, the SBC. The document has a renewed relevance to the chagrin of
some Baptist stalwarts who dug into what we would characterize as standard Evangelical (difficult word) beliefs.
Enjoy!