While it is common for people to be intimidated or scared of spiders, the truth is that most species we come into contact with are harmless. Examples of nuisance spiders are wolf spiders, house spiders, cellar spiders, and spiny-backed orb weavers. These spiders possess venom strong enough to paralyze their prey, but not enough to harm people.
In the United States, there are a couple of species of spiders that are dangerous to people, and you should always avoid them. These are the brown recluse and the black widow. Being bitten by either means a necessary trip to a medical professional.