Scary situation indeed! You handled it well.
1. How can i protect my son as well as myself in a situation like this?
-keep in mind that you DID protect your son as well as yourself in a situation like that! Don't overlook that fact. Could it have gone differently, of course.... but you DID WELL. We can all fantasize about carrying a gun all the time and never having anything in our strong hands, but unless you are really willing to compromise your life around always being armed and pretending you are "ready", that's not real. You make due with what you have when you HAVE to.
-That said, perhaps a Gunvault quick opening safe, as mentioned above, will give you quicker access to a handgun in the future. Maybe one in each room of your house, if you think that is realistic worth the effort and $$$.... ?
2. I had just gotten off work where i can't carry a concealed carry weapon on me. I did not have a gun in my truck that day and if i did, what do i do, strap it on me everytime i go into my house?
-Some people would say "yes"... I would say "if you want to, it is certainly an option". Of course, there is NO Reason why you would want to choose a gun that you would not ordinarily carry for self defense. The gun that Tom mentioned, for example, is not one that I recommend. I am not one of those instructors who doesn't allow shoulder holsters, Appendix Carry or other non-traditional carry methods in classes because of "I'm not used to it" safety concerns, but I do not allow "grip clip" carry with a round chambered. An unprotected trigger with a round chambered is a recipe for disaster....
-As noted above, there are options for securing a firearm in your vehicle while you are at work, etc.
3. Due to having kids, i do not keep firearms easlily accessible. How can i have a weapon readily accessible when walking into my house, under circumstances like i have described to you?
-Again, the Gunvault is a good quick option. There are others, but this is one that I trust. When your kids are old enough to know better and yet young enough to not have friends over wandering through the house, you might decide that exposed guns kept "ready" are reasonable options.
4. How do i handle myself as a citizen, when i have a loaded weapon in my posession while police first arrive to a high intensity situation like that?
That is a whole ball of wax! The good new is that we cover that information in an upcoming episode of The Best Defense. Some tips for now:
1. Don't be standing there with a gun in your hand when they show up. When you first see lights, hear siren or have any other indication that LE is on the scene, put the gun on the ground or in a holster (preferably) ASAP unless you KNOW you need it to keep bad guys at bay.
2. In your case, I would have recommended staying at the neighbor's house with your son and called/waited. No reason to go back to the house/yard/zip code where the bad guys are if you don't have to protect other family members.
3. Give the dispatcher as much info as possible, including the fact that you are armed and an accurate description of you and your clothing.
4. Answer the cops questions politely and professionally.