Tax on sale of rental houses

I wish to sell two houses and to use the proceeds to buy a house to live in. The amount from the two house will not bee enough to purchase my new home.

The house I currenly live in (worth more than the two rentals sold) will be used as a replacement rental for the ones I am selling. This house will therefore be rented out. Reason for all this is that I wish to be closer to my rentals so that I can maintain them more easily.

In this switch can anyone tell me what my tax liability will be and how I can minimise this?

Thanks