There is one poisonous spider in particular in New Jersey to watch out for while others are only react with a bite when provoked or if they feel threatened. For the most part, it is best to stay away from spiders since they can bite and it can hurt. Bites effect people differently. Where one person doesn't have a reaction another can get seriously sick from it.
Look outside on the ground in opened areas. You may find a daddy long legs or a Holocnemus Pluchei. This spider is very commonly seen and poses no threat. It cannot bite humans due to its short fangs, but if it could it would be dangerous. These spiders are best known for their long legs and pea size body. They have a rectangle abdomen and appear grey or brown. They can be found in cellars or basements as well.
Search your garden. You can find various spiders including the Black and Yellow Garden Spider. They like to live in gardens as well as in shrubbery and tall plants. Their abdomen is egg shaped and they are black with a mix of yellow and orange striped on top of legs and abdomen. They have short silver hairs and can get as long as 28mm.
Look around the outside of your house or barn and you can probably find the American House Spider. They usually spin sticky webs that appear in corners of homes or anywhere they are sheltered from bad weather. They are yellowish brown.
Beware of the Black widow. This spider is dangerous and will bite when they feel threatened. In particular the female black widow has a venomous bite whereas the male doesn't. They have a glossy black texture with a red hourglass marking on their abdomen. Sometimes they will have white or red spots down the middle of the back if they are not adults yet. They tend to remain in dark areas but can find their way into homes. They typically make their webs in dark areas that also protect them from bad weather.
Check out yellow or white flowers. You may find a Goldendrod Spider. They live among daisies in particularly due to its mostly yellow color. The spider is mostly yellow with reddish brown stripes down the sides of its body. These spiders are not aggressive. The Goldenrod spider also live in meadows and fields.