I imagine this might sound a little ridiculous to some of you, and hopefully brilliantly organized to others, but I really have found it cuts down my time in the store scanning through the whole list trying to find all the produce items or all the dairy items. I'm standing in the produce aisle and everything I need to get there is grouped together on my list.
Food Gawker and generally love anything Deb at Smitten Kitchen comes up with (plus she's so fun to read). I find myself turning to Barefoot Contessa cookbooks again and again. I recently let my subscription to Bon Appetit lapse because I have boxes and boxes of back issues. So I've started going through my old issues and tearing out recipes I want to try. If they're good enough to make again I punch holes in the page and pop it in my recipe binder, where I keep my favorite recipes organized by genre. If they're just so-so they head for the recycling bin.
And that's pretty much how I pull it all together each week! The hardest part by far is sitting down to decide on meals for a week but it's completely worth it to me to come back from the store knowing I have everything I need and also to be able to spend the rest of the week not obsessing over what we're going to eat. I just pull out my list and see what's on the menu that night.