Alrighty so let's get character creation started.
The first thing we're going to do is select the regiment we want to be a part of. This help determines some things like starting aptitudes, doctrines and what not. Training stuff.
Cadian Shock Troopers: Disciplined fighters from the ever-besieged world of Cadia where over 90% of the population is raised form birth to defend against the forces of chaos. You've held and handled weapons since you were old enough to crawl. Your tactics, uniform, and doctrines set the standard that all Imperial Guard regiments strive to follow.
Catachan Jungle Fighters: Born and raised on a death world with legendarily inhospitable conditions to human life you represent man's ability to adapt and overcome. A true survivor in the most hostile of situations.
Death Corps of Krieg: Conceived in rebellion and born of nuclear fire you come from a background of regimented self sacrifice and penitence for the crimes of your ancestors.
Elysian Droptroopers: From the fringes of space you have served a tour of duty defending your homeworld and hunting pirates, raiders and other terrors that come from the deepest ranges of space. Lightly armed and lightly equipped droptroopers specialize in dropping on enemies from orbit, from dropship, or from other airborne conveyances to surprise and ambush an enemy and conserving resources until the battle is won or at least until reinforcements arrive.
MAccabian Jannissaries: Driven by zeal enflamed by the deepest of faiths the Janissaries see their tour of duties as pilgrimages rather than military service.
Mordian Iron Guard: Supremely disciplined and organized your regiment comes from a planet where the unruly require a tight fist to keep order. You represent that order.
Tallarn Desert Raiders: On the desert world of Tallarn you honed your skills for the ambush and the well placed shot on the deserts and tunnels of your home. Guerilla warfare is your creed whether emerging from the dunes lasguns ablazing or thundering suddenly from the mountains astride a powerful leman russ tank.
Vostroyan First Born: You are the first born of your family and due to an agreement made way way before your time whether you wanted to or not you were sent off to serve the imperium in tithe. Your family considers this a great honor and you may have even met a relative when you were shipped off. Vostroyans take pride in their equipment often getting heirlooms from their family in the guard but nonethless of the utmost quality due to your homeworlds close relationship with the Adeptus Mechanica.
The Swordmasters of Yatagan: Raised on a feudal world where skill with the sword is cherished and respected more than the crude ease of lasgun fusilades your regiment relishes the thrill of close combat even against physically superior foes. Your regiment is known for its grisly trophies and unparalleled skill in close combat.
If you want more info fluff wise on the regiments all but the last one can be looked up via google and be provided an absolute wealth of information.
I made the last group because I figured something from a feudal world (i.e. has tech closer to the 1300's) might be more comfortable to those unfamiliar with the setting.
As far as people from a mix of homeworlds might be concerned we can discuss it but I'd like for most of the squad to come from the same homeworld.