My first recommendation is to go online and practice. This helped me greatly. If you are staying onsite you get the jump on 90+10, meaning you can make your ressies 90 days out and for up to 10 days. Now on Oct 27 they go back to 180 days in advance.
Some things that helped me were to have multiple tabs (windows) open and set for the restaurant I wanted on each page, then as I added adrs to the cart I moved to a new tab and refreshed, it made moving quicker.
Once your ressie is in your cart you have either 20 mins or 2 hours (I was out in 17 mins with 8 adrs) to check out or you lose them. So keep watch on the time.
Try to schedule your most important ones first, or the harder places to get into, whichever you prefer. Good luck and remember to have fun!