Tor Books publishes sci-fiadventureantasy http://www.tor.com.
So does Avon/Eos (an Imprint of Harper Collins) : http://www.harpercollins.com/imprints/index.aspx?imprintid=518005
Check the guidelines on line to see if these publishers will accept “unagented submissions.” If they don’t, you’ll need to find an agent who will represent your work.
You can find a good list of genre publishers at Ralan.com. Ralan lists both short fiction and novel publishers.
If you find you want to go the agent route, you can try http://www.agentquery.com to find an agent.
Hope this helps –
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