PERSONNEL

Okay, the vast majority seem to agree that the bigger group, the better the defence. I'll start by partially disagreeing with that. In theory a group of 6 people could defend a small structure, working in pairs on 8 hour shifts, or 12 hour ones when a pair are out raiding.
Down to the bare facts, in a world where almost nothing, if anything at all, is being produced, that means that there will be lessening amounts of food, clean water, ammunition, structurally sound buildings (as they will all fall into disrepair eventually) and appropriate protective gear. Therefore I summize that small groups are easier to supply with adequate amounts of all these things.

2 groups of 6-12 are better than one large group so, if manpower is available with enough supplies, set up a secondary base close by. So incase one base is over run completely, there is a small chance some of the survivors can make it to the other one.

LOCATION

Inland

good points-
no pirates to contend with, 360 degrees of land to expand, farm and loot/raid, more defencible structures(mainly), and possibly rivers for fresh water, likely that the local area is well known, widely predictable weather conditions.
bad points-
little means of producing power apart from fuel or human dynamos, raiders, risk of isolation, natural disasters e.g. floods/fires, rivers may be poluted, 360 degree defence needed, almost surely static defence so possibly no backup defence, higher Z count (normally).

Shore
good points-
means of escape in a pinch provided that there are any boats, fishing for food, fresh water when desalinization systems are used, hydro-electricity via watermills if you have the know-how, local area may be well known, and if its a harbour, the zombies can't come at you from the sea.
bad points-
if it is just a shoreline, possible risk of zombies wandering out of the sea, may be no boats there, shorelines are generally high industry areas so more industrial hazzards, weather conditions are really unpredictable, sea may be poluted, pirates and raiders will be a problem.

Offshore
good points-
much more easily defensible, fishing for food, no raiders, almost no industrial hazzards, hydro-electric power supplies, low/0 Z count, and lots of mobility if need be.
bad points-
harsh and unpredictable weather, becoming lost is a real problem, inexperience at sea?, may become over-confident/complacent with little need for security, lack of building materials and fresh water, no gaurantee of second line of defence.

I'd personally stay inland. I'd know roughly what to expect from the surrounding area with regards to hazzards and weather, and I'd know the most likely places for other survivors and provisions.

WEAPONS

Weapons at hand-
My stepdad owns two .22 rifles (scoped), a over-under shotgun (iron sights), and a number of melee weapons, including a battle tested trench-knife.

My ideal loadout-
SA80 A1 (scoped), 5000 5.56mm rounds, coachgun, 500 12ga shells, aluminium crowbar and a trench-knife.

CLOTHING

Bike Leathers or camo trousers and a t-shirt

PERSONAL GEAR

The stuff I'd keep on me at all times-
80L bergen, chest rig, 4 litres of water, ration packs for 7 days, mess tins, gas cooker, 2 spare gas bottles, all seasons sleepingbag, rollmat, 2 changes of clothes, main weapon, 3 spare ammunition clips, box of 100 rounds, weapon cleaning gear, map of the local area, 2 tarpaulin sheets, 2 bungie cords and 4 pegs (for a makeshift tent), and a few other things I can't think of off the top of my head.