Ok, here's the problem:

I have a 3 1/2 year old Rottie (we think he might be mixed with Lab
too because his face didn't widen) who is becoming *growly* as he gets
older and he is skittish/easily startled. Let me say I don't know the
first thing about training beyond sit, stay and down so I need advice
in the form of baby steps (dogs for dummies if you don't mind) He is
an inside, family dog and has been raised with love and respect and I
have figured out the root of the problem and fixed it (please don't
ask, it is a real sore spot right now), I just don't know how to train
this out of him. If I am to be able to keep him and not have to
re-home or shelter him I need to train him to be a nice boy instead of
a *don't mess with me* kinda guy.
First problem: He is afraid of everything that isn't supposed to move
but does (the vacuum cleaner, a laundry basket, the toy truck my 1
year old likes to push etc etc) I've had him since he was about 12
weeks old and I know noone has done anything like throw things at him
and my house is always noisy so I just don't get the jumpiness when
someone tries to carry something by him.
Second problem: He is getting more and more *growly* (dunno how else
to explain it) like if someone comes to the door he will bark and
growl and behave like he wants to bite...which of course I can't have
especially with a baby in the house. I need to know how to train him
to not be like that. He was ok when he was younger, not so possessive
but as he ages it is getting worse. I don't want this to end in a bite
and then having to put him down (my heart would break)
I can't afford to take him to a trainer (I'd love to take him to the
guy about an hour south of me who would keep him for 12 weeks and then
teach me how to train him to me but that's just out of the question)
Let me say I also have an 8 year old Shepherd that I didn't do
anything differently with as far as training goes and she is tolerant
and well behaved. I hope it isn't just the sex and breed difference
causing this and that I can correct this problem. Also My dogs are
with me all the time within the house. They go out to potty and play
for a few minutes several times a day but that's about it.

Anyone have any advice for me? (without biting my head off please,
that won't help and I really want to help my dog) I am a stay at home
mom and have tons of time to do this so if your suggestions are time
consuming it's ok cuz I got all day

Thanks
Jen