my structure

Hello ,
I just got a mikrotik to my office , it seems realy good but i need some help on the configuration;

http://img411.imageshack.us/img411/9311/structure.jpg

I would like to setup a load balance between the 2 adsl’s and to give manually public ip to my server !
I wont to give priority to the voip network over the public servers and separate the voip/server network from the pc network.

could you tell me what configuration should i make to mikrotik and what subnet and gateway sould i give to my server?

noone ?
is that so difficult?