Kurt Harris' guide is extremely helpful.
Mark Sisson has a great guide compiled in his Definitive Guide series.
Here's a sample:
PROTEINS: Chicken breast Chicken thigh Flounder Snapper Trout Halibut Mackerel Bass Salmon steak Salmon fillet Shrimp New York steak Rib eye steak Round steak Ground beef Beef ribs Rump roast Beef stew meat Pork loin Pork chop Pork ribs Baby back ribs Bacon Pork roast Lamb chops
VEGETABLES: Asparagus Avocado Artichoke hearts Brussels sprouts Beets Carrots Celery Daikon Zucchini Fennel Root Kale Chard Dandelion greens Spinach Acorn Squash Butternut Squash Yam Sweet Potato Red pepper Yellow pepper Green pepper Red cabbage Green cabbage Napa cabbage
FATS: Coconut oil Olive oil Macadamia oil Avocado oil Lard
HERBS & SPICES: Allspice Basil Cardamom Cinnamon Celery seed Dill Fenugreek Garlic Ginger Curry-Red Curry-Green Curry-Yellow Oregano Cillantro Nutmeg Rosemary Thyme Garam Masala Bay Leaf Salt Herbs de Provance Chili powder Paprika Cumin Black pepper
Grains (all grains: wheat, rye, barley, spelt, corn, rice) Legumes (peanuts, beans) Dairy
Jeanie, welcome to PH!
Have a look around first at what questions have already been posed and discussed in detail. The search feature is very robust so you can usually find what you are after. This will give you a good general idea of what to ask :)
This question has been asked and answered a lot. Review the archives.
Simple answer: Animals & Plants.
More Complex: Meat (& eggs & fish, favor ruminants(cows/sheep/bison)), Veggies, Some starchy tubers (unless diabetic or trying to lose weight), Some fruit and nuts (think only seasonally available - also depends on goals), Insects (just kidding), Dairy such as cream and butter are not strictly paleo, but useful for a higher fat diet.
No grains, No vegetable/seed oils, No sugar/flour/fructose, No legumes. Aim for at least 80% compliance (Ie 1g sucrose in a square of very dark chocolate ain't so bad; coffee/tea/red wine in small amounts are probably okay... Even Dr. kurt Harris cops to eating gas station M&Ms and rancid WalMart cashews in moments of weakness)
Get vitamin D levels up (sunshine is best). Take a look at other nutrients (magnesium/K/fish oil are biggies). You are good to go.
And welcome to PaleoHacks!
Orthodox paleo proscribes sugar (fructose), grains, legumes, dairy and nightshades (Cordain, Wolff).
Neo-paleo proscribes gluten, excess fructose, excess linoleic acid (Harris).
Therapeutic paleo for the metabolically-deranged/insulin-resistant/obese/carb-addicted (like me) is zero carb (ie meat and water) (Charles Washington of zeroinginonhealth.com)