If you are following BLS - give dairy as soon as you feel like it.
We gave DD cheese early on.
yoghurt was introduced when she was able to feed herself... again in line with BLS you shouldnt be 'feeding' your baby.
i cant remember the exact age that MJ had yoghurt, but i gave her only plain youghurt and sweetened it with pureed fruit. that way i knew what she was getting in terms of sugars etc.

Go with your gut, there is so much arguement for and against this issue, i am from the school of thought that says that early introduction can stop allergies, but of couse i have no allergies with MJ, if she did that may be a different story... what i can say is that BLS says if there is no DIRECT allergy link(ie mother father sibling not uncle aunt cousin) then there is no need to delay.
I think i have said this in PP to you though, YOU have to be comfortable with the decission that you are making.

FWIW a lot of formulas are dairy based - something to think on!

ETA - we gave cheese as small sticks or grated cheese