Soooo, let's start from the beginning...
You have your diablo and DB open, then you should setup bot settings: click on the down arrow near "settings" and select "bot". set your options
Then, you have to select some options from trinity: click "plugins" on the top, click on "Trinity" and then "config" on the right. Select your setup (you can leave 90% of the options as they are, I have never edited my combat routine and it works fine)
for the other questions, you have to find what profile you want from the forum, download it and load it into DB clicking "Load" near "Settings" in the main section of the bot. Profiles are your routes, where your bot is gonna farm. Some profiles requires more plugins and/or some settings/quests selected, but you will find how in the same page you download them.
To select your combat routine, you simply have to login into your char and the program will play it based on which spells you have. when asked, remember to select "Trinity" as your combat routine.
To sell rare/blue and keep legendaries is a little bit more tricky. You have to find in the forum a loot profile (look under profiles/others) and you should find what you are looking for. You will have to set something under trinity, but as usual, where you download the profile, you get indications about how to make it work.
I know that this seems a little bit complicated, but you will get used to it in a copule of days and then you will use DB at his full potential.
P.S.
A bot is not smart... don't do the max possible torment, try to lower the difficulty a bit ^^
if you need any help I'll try to answer
EDIT: Everything you need is in this forum. Surf this forum alot and find what you need, test it out and if you don't like it there are tons of other profiles / plugins / settings for you.
