So my Pedi is basically useless and has told me nothing, I'm hoping to cover all this at DS's 12 mo appt but in the mean time I want to know what to expect.
So I know after a year they switch to whole milk, but that's about it. Do you slowly wean them from formula and switch to milk, do you just stop giving them formula the second they turn 12 mo? Can you give milk in a bottle or should it be in a sippy?
I can see DS starting to drop bottles in the future, and is already drinking less of his formula and eating more food at meals. But after that I'm lost. We're working on the sippy concept, but he doesn't want anything to do with it.
How is everyone else doing the transition?
Re: About the whole milk transition...
I would do a slow transition when he turns 1, for example, say he drinks 4 bottles a day of formula right now, I would substitute 2 for the whole milk and keep 2 formula. After a few weeks of that and he is digesting things smoothly go down to 1 bottle formula and 3 whole milk. Then eventually cancel out formula all together. I would say the transition process from formula to milk should take 3-4 weeks after he turns 1.
I've heard a lot of moms say they still give 1 bottle of formula per day until 18 months because it's like a multi vitamin for baby. That's your choice.
This is what we did with DD1:
At 12 months, we started mixing formula and whole milk in her bottles (3 bottles a day). We started with 4oz formula and 3 oz milk, and worked our way up to all 7 oz being milk. Just upped the milk and decreased formula every 2-3 days as long as she was handling it well. So by about 2 weeks after her birthday she was completely on whole milk, and at that point we dropped her afternoon bottle and gave her a snack and milk sippy instead.
At 13 months, we dropped her wake up bottle for breakfast and milk sippy, and at 14 months we dropped her bedtime bottle for a milk sippy. We started offering milk in a sippy at meals around 12 months.
We'll follow a similar timeline for DD2, except I think we'll switch to all sippies sooner since she does better with them and DD1 did.
DD1 Feb 2010
DD2 Sept 2011
This is my method...take it for what it's worth.
I started by putting 1 oz milk with 5 oz formula in each bottle for a couple days then go to 2 oz milk 4 oz formula for a couple of days, today we started to go half milk half formula and prob late tomorrow or Saturday we'll go to 4 oz milk 2 oz formula and then eventually end up with an all milk bottle. I hope that makes sense to you...it does to me as I'm typing but it may be clear as mud! 
In answer to your question, I live in Canada and the recommendation is to start introducing WCM around 9 months.
When LO was 9 months we started introducing 2 oz at dinner in a sippy. At 10 months we added 2 oz at breakfast and plan to add 2 oz at lunch when he turns 11 months. This is meant for practice and not to meet his nutritional needs. We still BF 5-6 times a day.
Personally, I wouldn't put it in a bottle given that babies should start to be weaned from the bottle around age 1. I would offer it in a sippy. If you notice LO turns their nose up at it, you could always mix it with formula and each day put less and less formula into it. Good luck!
Our family blog
We started introducing a sippy with meals with whole milk at 10 months or so, she didn't really drink much, but it was a starting point. I had been BFing and my supply tanked, so we have switched to whole milk completely at 11.5 months now. We just started mixing her bottles part BM and part WM and increasing til it was all whole milk over the course of about a week.
As far as the bottle to sippy switch, we currently give bottles before naps and bed time and sippy cups otherwise, which we started at the same time as the switch to whole milk.
I pretty much did the same routine with my oldest and it has gone quite smoothly both times.