Max settlement population = 10+ your Charisma Special.
So you will never need more then 21 beds, 21 food, or 21 water per settlement. (Possible to have 10CHR then get the CHR bobblehead. = 11CHR) Unless you want to establish trade routes and dedicate a settlement to growing water/food so the others will not have to.
When you visit your home after the bombs go off, pick up a comic book in your kitchen and the SPECIAL book in your baby’s room. It will give you a Special Point. Also, look around the homes there, one has a cellar on the outside with some starting gear.
Carry several weapons that use different ammo types.
Put at least one point into Scrounger, you will come to appreciate ammo more then caps. I rarely use merchants other then to sell stuff or buy a specific ammo type I may be low on.
Figure out what types of weapons you want to specialize in for your perks. Pistols/Automatics/Rifles-Shotguns/Big Guns.Technically there is no level cap, but I suggest picking 2 types and sticking with them with most of the game.
Putting points into lockpicking and hacking early on will yield some nice rewards.
Put a point into Lady Killer & Threaten if you want to talk your way out of most situations.
Use quick save in the middle of talking to people for speech checks if you want to keep trying until you succeed.
The more intelligence you have, the more Experience points you get for everything.
Research companions before you start the game and figure out which companion perk best suits your playstyle. Some are only available with optional side quests, so doing the main missions means you may never find them.