Get to DHS early....an hour prior to opening is not out of the question. There are 3 events at SWW that will become mob scenes quickly. They are Autographs, exclusive merchandise, and character meet and greets. If you want to do all three there is a good chance that you will need to attend at least 2 to 3 days to get it all in especially if you do not want to deal with crowds.
If you plan on getting exclusive merchandise do this on your first day. Pins will sell out quickly. Higher dollar, and larger production run items items tend to last a bit longer, but if you want the pins you will almost always need to be there on Friday. The merchandise store tends to clear out around noon or so if you just want to see what is there that is the time to go.
If you want autographs there is a good chance that you will need to get there extremely early depending on who is there. For example 2 years ago when Ray Park (Darth Maul) was there the line for autograph fast passes started to form at around 3:00 AM. I got there at 6:30 AM and had to settle for a stand by pass.
For the character meet and greets arrive around a half hour of more before opening head straight to the meet and greet sites and you can usually run the gauntlet in a few hours.
Grab a times guide first thing. You should be able to fit in most of the other activities such as Behind the force and Stars of the saga with a little bit of planing.