I heard that NPC's sometimes attack your home. Can you hire guards or if you're a conjurer get Daedra to watch your place?

Nope, only people at you houses are your housecarl. You can add a steward, wife/husband, and child(children).

Normally your steward, housecarl and of course yourself can take care of the job of defending your home. Attacks shouldn't happen when you aren't in the cell.

Oh alright. Though if you can be attacked you would think they would allow you to set up some kind of defense.

I've only been attacked by bandits so far. There isn't much to their game plan besides run up to your house. I'm not sure about spouse, but I have a combat ready one and I don't have kids (but kids can't die anyways).

My steward is normally inside but I did see him run out to defend during one of these attacks.

Having guards would be redundant. Housecarl, Steward, Spouse, all armed to the teeth is a pretty formidable obstacle to any attackers. Just be sure to arm everyone with some nice weapons. It would probably be good to pick a spouse that is either essential or at least levels with you.

I have Lydia as my wife (thank you 1.6 patch), jordis as my steward, and the housecarl Gregor. I'm almost hoping for someone to try to invade my house

I made the mistake of making my housecarl my steward when she asked. Now I can't have another housecarl at my house (I tried having Lydia over, she just left :c) or another steward. At least I have my bard, his drums make for a good battle tune lol.

This. And don't forget the horse. They'll jump into the fray as well.

When i was at the house in Falkreath i was attacked by bandits with maybe a small ( yet stupid ) gameplan. The bandit Cheif and his mage attacked me out front while i was adding on a new room, while the marauder ran into my house, i slaughtered the 2 outside then transformed into a vampirelord and entered my house. The maruader attempted to flee but were they didnt let me finish my other room there was only one door....and a Vampire Lord stood in front of it.

Sounds like a fun battle

I can see the op point, I mean, this style house looks like the start of a new town so why not have some hired guards or atleast mercenaries kind of like what the Black Briar farm has down in riften. Also have the option of being able to equip your mercenaries much like you can equip the house carls.

Not sure if they fixed it since the beginning.. I havn't tested it yet on my version (updated with Dawnguard) but do housecarls actually stay in the gears you equip them with after you leave their presence?

I have yet to see bandits make it inside, I didn't think they would enter. None of them have survived that long to see. Last thing I need is to mess up the rooms because item placement is a PITA!

You can get a dog.

I agree about the item placement...i knocked over a book while running around the bedrooms and its just laid in the floor, i tried to pick it up and place it back on the shelf but when i came back it was on the floor again. I tried to make my kids do their chores thinking maybe they would pick it up and being an NPC did it maybe it would stick....but no, they just left it in the floor. I eventually had to just pick it up and sell it.

Dragonborn + Housecarl + Steward + Spouse + Dog + Invincible children + Horse = better security than any city can have.

I think you're pretty safe.

You can also have a follower, or even two followers if one is Serana.