a 11 months is REALLY early to start potty training and the earlier you start the longer it takes to train them. Most boys arent really train able until at least 2.5 yrs. there are several things that they need to be able to do before they are ready to be potty trained its not just hey lets buy him a potty and make him go thing. It dosn't work that way they have to be showing interest first.
Physical signs
Is coordinated enough to walk, and even run, steadily.
Urinates a fair amount at one time.
Has regular, well-formed bowel movements at relatively predictable times.
Has "dry" periods of at least three or four hours, which shows that his bladder muscles are developed enough to hold urine.
Behavioral signs
Can sit down quietly in one position for two to five minutes.
Can pull his pants up and down.
Dislikes the feeling of wearing a wet or dirty diaper.
Shows interest in others' bathroom habits (wants to watch you go to the bathroom or wear underwear.
Gives a physical or verbal sign when he's having a bowel movement such as grunting, squatting, or telling you.
Demonstrates a desire for independence.
Takes pride in his accomplishments.
Isn't resistant to learning to use the toilet.
Is in a generally cooperative stage, not a negative or contrary one.
Cognitive signs
Can follow simple instructions, such as "go get the toy."
Understands the value of putting things where they belong.
Has words for urine and stool.
Understands the physical signals that mean he has to go and can tell you before it happens or even hold it until he has time to get to the potty.
This is just an example of the skills that are identified as potty training readiness.
here is a website for more information on potty training.
http://www.nncc.org/guidance/toilet.train.html
when you do start I would recommend starting on the big toilet instead of getting him a potty chair, that way there's no transition trouble to the regular toilet.
again Boy's take longer than girls. My son is now 3.5 and has been day trained for about 3 or 4 months. I started early with my daughter and it took over a year to get her day trained.