First, you need to choose your character concept. While the "what" and "how" of your character can be incredibly diverse in Shadowrun, a successful party of underhanded criminals usually has some of the following types of characters:
The Face of the group is the one who negotiates and leads for the party. When accepting jobs in smoky nightclubs or exchanging packages in rainy alleyways, the Face is always the one who uses charm and a smile to get their party the best deal. Faces also excel at doing their research and calling upon their large pool of contacts to gather information and ensure success on the job. It's not all smiles though; the Face knows when a deal's gone sour and the guns need to come out. Faces prefer using words but have no problems drawing the holdout pistol hidden in their coat or implanted into their palm.
Faces thrive off of good Charisma and Willpower stats, as well as Dexterity just in case bullets start to fly.
Spellcasters bring the power of magical spells to combat situations. They channel mana in various ways to bend magic to their will and use it the way it most benefits them. There are a few different subcategories of spellcasters, all based off of how they choose to channel the mana they control.
Magicians take a logical and ordered approach to mana, using it to quickly achieve direct goals; zap a security guard, heal your buddy's bullet wound, and sweep up that police car in a tornado— all in the same turn. Magicians enjoy high Intuition and Willpower stats to keep the spells flying and the chaos everywhere.
Shamans, on the other hand, take a much more instinctive approach to magic. They use their mana to call upon the forces of nature, which tends to be slower but more powerful. They charm aspects of nature and spirits into doing their bidding on the battlefield. Shamans benefit from high Charisma and Willpower in order to keep their army of fire, earth, wind, and water spirits in line.
Adepts use mana in the most intuitive way possible: channeling it into their own bodies to enhance their capabilities. They use mana to give themselves superhuman abilities: to jump higher, run faster, punch harder, and dodge quicker. While they won't be casting any flashy spells, they'll be pulling off impressive displays of hand-to-hand combat. Adepts have high Body and Willpower stats to keep fighting, with some Quickness as well to keep the fighting fluid.
It's 2075, and technology is everywhere. The Decker takes advantage of the Matrix, the wireless lattice that connects all computers, commlinks, databases, and security systems. They use their trusty cyberdecks to jack in and jack off— meaning that they manipulate data, break security, and take control of systems so their party can infiltrate even the most secure facilities. A good decker can juggle hacking into a system and firing a pistol in the middle of heated combat.
Logic, Intuition, and Willpower are important for Deckers, since they need to handle firefights and code at the same time without cracking under pressure.
Technomancers take hacking to the next level. They can access the Matrix without the need for technology at all; they use a narrow offshoot of mana called resonance to log on with only their mind. While their control of technology is more intuitive and total than a Decker's, their combat skills are below par. Just like Deckers, however, Technomancers live off of high Logic, Intuition, and Willpower.
Riggers are constantly tampering, fixing, and improving their arsenal of drones and gadgets. They work hard on keeping their remote-controlled creations at the top of the line, but when their drones come 'round the corner with enough ordinance to conquer a small country, it's all worth it. Riggers are ace controllers of machines, their drones, and any gadgets they whip up. They supply surveillance, transportation, and remote firepower to their team.
Riggers require a high Reaction stat to simultaneously manage all the drones in their arsenal effectively.
Street Samurai are artists of pain. When they're sitting down for a nice meal, they've got fifteen different ways to kill the guy sitting across from them with the burger they're holding— and still eat it afterwards. Street Samurai can take large amounts of punishment and stay standing, usually by augmenting themselves with serious amounts of mechanical limbs and implants. Street Samurai are often the commanding force on the streets, and just the mere sight of them will send amateur gangs running.
Street Samurai use Body, Strength, and Agility stats to draw their katanas and make the heads roll.
After you have a vague idea of what your character will be, head on over to the next step: Metatype