Checklist before buying a Company

We are in the process of buying a "Limited" company from its current owners. The deal is simple; we pay them X amount and they will relinquish their ownership make us owner.
What all legal precautions should I take to make sure I am  protected and there is no trouble in future. 
The company currently has many partners but it will be under single ownership after take over.We are buying it as individuals.