Low-security space is many things to many people: a pirate wasteland, a source of income, or a proving ground for fighting skills. For some it is even home. Low-sec solar systems stretch between and around the safe areas controlled by the NPC empires as a sort of hazard zone. Low-sec has such a bad reputation with new players that it is generally considered suicide to enter it, let alone spend time there. This is a guide for new players to help familiarize themselves with low-sec and the low-sec mentality.
The Unique Particulars
Low-sec is a kind of free for all: PvP is not punished by CONCORD and space cannot be conquered by players. Instead, pilots that take aggressive action against others are attacked by automatic sentry guns that surround all stations and gates. If a fight takes place away from that, though, there is no assistance for hapless victims. Indeed, in most cases the attackers are prepared for the sentry guns and triumph despite the defender's extra advantage.
There is also the matter of security status: making unprovoked attacks on other players will lower one's security status. Do it enough and parts of high-sec will slowly become off-limits. First solar systems with 1.0 security status, and then steadily more until you are confined to areas outside of high-sec. It also clearly identifies a player as a ne'er-do-well. It's not all bad, though: a low security status is sometimes worn as a badge of honor by pirates and PvPers.
There are also some pleasant features for travelling pilots: area of effect warp disruption cannot be used in low-sec. This includes the effects generated by interdictors, heavy interdictors, and mobile warp disruptors. This means that a small, fast ship can likely warp between gates before anybody can lock it. That doesn't stop pirates from using remote sensor boosters and trying, though.
The Lucrative Features
The planets in low-sec are incredibly rich in resources.
Since it was introduced, planetary interaction has become a major cash cow, especially for new players. With less than week of skill training, a well-organized player can pull in hundreds of millions a month from planets. Alas, the planets in high-sec are slim pickings, with outputs significantly less than their counterparts elsewhere. Competition from other players for those same resources makes high-sec an even less palatable option. So people go into null-sec if they are in an alliance, and the rest of us go into low-sec. The planetary materials are plentiful, the competition is sparse. Even losing a hauler every two days will still not put you in the red. The trick is finding the right spot. One or two jumps out of disused high-sec gates seems to work for most.
The Brazen Inhabitants
Low-sec has never really been well populated, aside from a few PvP hubs. Solar systems like Amamake, Rancer, and so forth are pretty much PvP arenas full of various pirates trying to bait each other into fights to see who has the sneakiest trick up their sleeve. When faction war came along, some medium sized fleets began appearing as the four empire militias began duking it out, and some moderate populations began moving into little clusters that became de facto headquarters for each of the factions.
There are also dusty corners where small corporations happily practice PvP in their chosen forms, usually piracy or pirate hunting. Functionally there is not much difference between the two, though the pirate hunters seem to have better networking with each other.
More than any part of null-sec, the politics of low-sec are fundamentally local. The people that stick around an area come to know each other and whether they are a threat or not. Players out there tend to get an intuitive understanding of their surrounding locations and inhabitants. This is hard to come by without living in an area over time.
Why then, should new players care about low-sec? Because it is a readily available source of PvP that is relatively porous with high-sec space. Ideally, players from high-sec would be able to get into null-sec and experiment with PvP there, because the game mechanics are intuitive and relatively un-encumbered. Unfortunately, the most ready access points from high-sec to null-sec are camped by pirates or bored alliance pilots for much of the time. The alternative, then, is low-sec, which is as often not camped as camped, especially if your egress there is not too close to Jita.
There are a few advantages to low-sec for new players: frigates cannot withstand fire from the sentry guns, meaning there are no unkillable dramiels wandering around. Also fortunate is that drakes, arguably the most popular ship for new players, are quite capable of withstanding said fire. So if you can afford drake losses you may be able to do some damage in low-sec.
More than anything, low-sec is probably useful as a place that is inherently dangerous. It gets players' heads in the right place about always being on your toes, trying to anticipate and stay one step ahead of potential threats, and operating in a hostile environment. Much more than high-sec, which for most players is pretty darn safe, it is this notion of constant danger that turns new players into diehard EVE veterans.