You have to be willing to stick with real foods and not prepackaged junk. If you can focus on true low-carb options, this will ultimately help you curb the traditional cravings for breads, rice, pasta, sweets, etc.

I would suggest you visit Atkin's website. They do give a GREAT and simple list of foods you can eat on each different phase. In its easy-to-read format, you can also find recipes there as well.

I'm in the UK, so products available might be different for you, but I'd be stuck if I didn't snack on peperami sticks, Mini Babybel cheeses, macadamia nuts (I'm pretty sure you can find those!), and if I want something sweet I make some weird cream + cocoa powder concoction with sweetener, although I want to phase sweeteners out completely. In an emergency I make a protein powder shake, but again these are sweetened (and pretty unnatural) so on the way out for me.

As far as meals go, for evening meals I tend to just think of meat + two veg and don't get much more adventurous than that. Others in this group have far more gourmet meals! So I'll have steak with broccoli and cauliflower, or roast chicken with salad leaves and green beans, where other people make spaghetti squash bolognese, or wheat-free pizzas. It's just a question of how lazy or busy you are, and I'm VERY lazy!

Tips for keeping under 20g carbs- try to get your carbs from vegetables rather than dairy. It helps to have cream instead of milk, and limit cheese and nuts (or cut them out completely to start with). Like cramer says, watch out for processed foods, including packaged meats, they often have sugar or starch in them along with a load of other nasties.

You will need to drink more water than normal when in ketosis, at least to begin with if not permanently (I've been mostly ketogenic for a few months and still drink way more water than I used to).

I hope this doesn't put you off, but I have only one other piece of advice. If you think you're a serious carb addict (usually significantly overweight, have little control around things like chips, chocolate, sugary things, doughnuts etc and find low calorie doesn't work because you binge), you might get some temporary negative effects from restricting carbs to 20g or under. It's like sugar withdrawal, basically. This might mean a few days of one or more of the following: headaches, fatigue, weird or vivid dreams, insomnia or leg cramps. The muscle pain can be avoided if you supplement with potassium. I'm saying this because too many people freak out and give up. This phase- if you get it at all- DOES pass, really quickly, and afterwards most people report feeling much, much better.
Best of luck- report back on your progress!

Check out the Launch Pad, where we have gathered some helpful threads, recipe site, book recommendations, and videos.
The LCD Launch Pad

We are here for other questions we haven't yet addressed on the LP. It's a work in progress. Happy Low-Carbing!