I'm thinking of becoming a vegetarian and I have been eating meat for all of my life until now . If I stop eating meat all of the sudden will I get sick or something and are than any tips or special guidelines to follow while being a vegetarian?

The best advice I can give is this, (there are a few different types of vegetarians,) but the basics are:
Build meals around proteins that are low in fat, like beans, lentils and brownrice. Don't add high fat cheese to replace meat. Calcium fortified soy based beverages can provide calcium in amount as milk. Try eat pasta primavera or pasta with marinara or pesto sauce, a veggie pizza, veggie lasanga, tofu veggie stir fry, veggie kabobs, bean burritos or tacos. For breaksfast try soy based sausage patties or links, try veggie burgers, their made with soy beans, veggies or rice. Add meat subs, to soups or stew to up the protein without adding cholestrol or fats, tryy tempeh, tofu or wheat gluten products, try veggie bugers, soy hot dogs, and even take burgers. Make bean burgers, lentil burgers, or pita halves with falafel (spicy ground chick pea patties), Vegetarians can meet all nutritional needs with the right variety of foods, nutrients that vegetarians may need included iron, protein, calcium, zinc and vitamin B 12. Sources of Protein are iron fortified cereals, spinach, kidney beans, black eyed peas, lentils, turnips, molasses, whole wheat breads, peas and dried fruit.
For calcium eat, soy products, OJ, dark green leafy veggies, and milk products, For Zinc, white beans, kidney beans, and chick peas, wheat germ, pumpkin seeds, For vitamin B 12 milk products, eggs, and fortified foods, soy based beverages, and veggies burgers and nutritional yeast. That's at least a goodstart for you to consider

I would suggest that you have to become an expert in nutrition so that you don't do harm to yourself by eating innappropriately.

First of all, you need an outline of a daily menu to follow relilgiously. You need to know how many grams of protein you need a day and where to get that protein(milk, beans, eggs, etc), how many fruits and vegetables, how much cereal grains, how much calcium, and so on.

Good luck, vegetarianism is the was to go if done correctly!

Just eat tofu, and protein.