Going shopping for my new vegan diet, ideas on what I should buy?!

Daiya cheese or nutritional yeast.
Dried beans (cheap, nutritious, easy-to-make, and YUMMY).
Brown rice
Miso (if you can find it)
If you like to have salads, you can make a creamy dressing with Veganaise (also good in macaroni salad)
8th Continent is my favorite soy milk
Tempeh (very good for you and versatile). It's a bit like tofu.
Try to find a vegan cookbook while you're out (before the grocery of course)

And when you get tofu, get the firm kind unless you plan to make a dessert with silken tofu. Firm is a bit more meatier and hold its shape better.

Try some leafy greens to steam (mustard greens are in season). If you don't have a steamer, you can put a colander in a big pot (so long as it's not touching the water) and cover the colander with the lid. Bok choy, kale, swiss chard are also very good. Spinach too, of course.

Also, don't forget any sauces you might want: soy, spaghetti, hoison, etc. Try sesame oil too, if you like Asian-style dishes.

Have fun!

ETA: @Daisy: Never said it had B-12 did I? It's cheesy-tasting, which is why I suggested it with the Daiya cheese. Most nutritional yeast is fortified with B-12 though. I buy it in a bulk section, so I don't have a specific brand to suggest.

Just a note of warning. Nutritional yeast does not naturally have B12. From VeganHealth:

"Brewer's and nutritional yeasts do not contain B12 unless they are fortified with it. At least two vegan B12-fortified yeasts are currently on the market: Red Star Vegetarian Support Formula and Twinlab SuperRich Yeast Plus. Unfortunately, there are some drawbacks to relying solely on B12-fortified nutritional yeast for B12:

Nutritional yeast often comes from bins in health food stores. If not careful, it would be easy for a store employee to order the wrong nutritional yeast out of the distributor catalogs which often list many yeasts. It would also be easy to accidentally put the wrong yeast into the Vegetarian Support Formula bin.
B12 is light sensitive. Nutritional yeast is likely to be exposed to the light because it is often stored in clear bins or plastic bags.
At least one vegan who thought he was getting B12 from nutritional yeast developed B12 deficiency symptoms that cleared up upon taking a B12 supplement.
If you are trying to use Red Star Vegetarian Support Formula for B12, make sure you are actually getting what you think. It is also best to keep it in the refrigerator or freezer, out of the light.

Please note: Red Star Vegetarian Support Formula nutritional yeast has many other nutrients and I eat it myself; but vegans shouldn't rely on it for their sole source of B12, in my opinion."

http://www.veganhealth.org/b12/vegansour…

Beans, at least one can of each kind, although I would suggest two-three cans of black beans and also kidney beans to be in your pantry at all times. Also, Couscous is great to have on hand for a quick meal, such as lunch. Today we are having Bush's Vegetarian beans on toast for lunch. Get a few 15ish oz cans and 28ish oz cans of diced tomatoes as well. These are great in many recipes. I also like to keep a variety of frozen veggies in the freezer such as broccoli, cauliflower, bell peppers, asian stir fry starters, and of course corn. Frozen corn bags are vital. I usually throw a couple scoops of frozen corn in many of my dishes. A can of black beans and a cup or so of corn go great with Couscous and also Quinoa. These are good things to have when you are trying to find something to eat, you can use them for hundreds of meals and it's nice to have things like that around.

Look for anything in the dairy free section - often they have vegan things like cereals, snacks etc nuta and pulses, lentils always good base for soups, curries etc... stock cubes for soup which is always a good lucnch/dinner when vegan! smoothies for breakfast, margarine instead of butter on toast (vegan bread). ALSO look for iron and protein and other supplements for your diet but check with a nutritionist or doctor.

Nutritional yeast! You can use it to make cheesy sauces, as a snack topping.. it has tons of uses. It's super healthy, high in vitamin B12 and will get you some protein. I've tried the Bob's Red Mill and the stuff in Whole Foods bulk section, both are really good.. some other grocery store brands don't have the best flavor.

Also, I would recommend trying some of the other kinds of faux milk. Soy is my least favorite. I prefer hemp, rice, or almond.

http://www.loveveggiesandyoga.com/2010/0…

Oh I LOVE Quinoa. My local supermarket has it ni bulk for $4.49/lb. They also have it packaged I think around $3 -$5. But Costco has a 4lb bag for under $10.

Nuts. Whole grains, like quinoa, but also any other whole grain. And beans.

bad idea and potentially catastrophic for anyone under about 23, it's very difficult to provide essential nutrients on a vegan diet regardless of what you may have been told

Eat meat you idiot.