load balancing scenario

Best Solution for my dual wan case scenario
Thanks for all you guys who help newbies like me.
My case scenario is:

  • My WAN access is provided over an Wifi connection (an wifi AP + 24dbi antenna connects to the school where I work). This access provides me an average 12 Mbps (download) and just 400 Kbps (of upload).
  • I have another WAN access over a 3G connection; this one provides me 4 Mbps (download) and about 2Mbps (of upload).
  • From my school I’m able to access my camera surveillance system (IP cameras which are connect to several wifi APs, that provide coverage to my home). The link between my home and my school is about 48 Mbps.
    So my question is: maintaining the services that I have, and taking in account that I own a Mikrotik RB2011, how can I take advantage of my extra 3G connection.
    Which is the best load balancing scenario for me, taking note that one of the WAN accesses has better download performance and the other WAN gets better upload marks?
    So could you point me in the right direction,
    Thanks in advance,
    Vítor Manuel