Hey Marianne,
This will be my 4th SDCC (San Diego Comic Con), and my second as a photographer for
www.toymania.com First, here's some very basic advice:
1. Wear comforatable shoes, this cannot be stressed enough, you'll be doing a lot of walking. The convention center is enormous, and there's a whole lot to look at.
2. Make a quick budget, you'll see a lot of fantastic things, and money goes quick if you're not careful. Plan food before hand by either bringing a lunch, or searching for an affordable place to eat.
3. If you can, get to the convention center early, there are alway long lines for both buying tickets, and waiting to get it.
Now as far as free stuff goes, there's lots!!!! When you register you'll be invited to walk around a large table full of freebies, from cheap paper leaflets, to nice t-shirts, and everything in between. Movie posters for summer blockbusters are very common freebies, but they go quick. Also, when you're walking the convention floor keep your eyes peeled for booths giving stuff away, or people walking around handing things out, always be sure to peer into large crowds and see what's going on. Last year I got free action figures like mad, people just handing them out. Lastly enter every singe contest drawing you can, lots of fun, and your chances are just as good as anyone elses.
As far as the LOTR EE preview, first find out where, what time, and what day it's at, and second be prepared to wait. Screenings such as this are always extremely popular, and there's only so much seating. My advice would be to check near the area where it's showing about 3 hours before the start to see if a line is developing, then if nothing is there check an hour later etc. Once a line starts, jump in, it's going to get long!
Most importantly HAVE A BLAST.
Hopefully I'll have some pics of cool Disney stuff to share with you all upon my return.
Hope this helped!