I just did both this am. I started @ 6 am (3 am my time.)
Make sure you have an account that you log into w/ Disney already set up on their site. I pulled up the site @ 5:55 am, went to make reservations, started to make a reservation and a little warning box appeared under the date which said that I was trying to reserve more than 180 days out and if I was a guest to link to my resort ressie, I clicked on the highlighted text, logged in, entered my reservation number (have that handy) and proceeded to make my ADRs. I had a list prepared w/ backups and knew which would be hard to get and went for those first. Have your credit card handy if you are getting any ADRs that require cc guarantees (CG and Akershus in my case.)
Since we have deluxe dinning for 10 days, I had a lot of ADRs to make and either my connection or the WDW site quit at 6:45, so at 7 am (4 am my time) I called and got the rest of my ADRs w/ a cm. Note, I wasted a lot of time on the computer searching for a lunch ADR @ Garden Grill, not realizing that GG doesn't do lunch.
My computer ADRs showed up on this great list on the WDW site as I entered them, but I had to add the phone ones by 'retrieving' them one by one by entering the confirmation number and my phone number on the site and now they all show up on the WDW site sorted by date and time.
Whew!