Orion xtreme 800.4

hello, i recently purchased a orion xtreme 800.4 amp. i was getting ready to hook it up, and a couple things cought my attention that wasnt on my last 4 channel amp.  Where i plug in the remote wire, under the part that says Remote, it has 2 spots that says remote gain, lookin like u plug somethin into it like a rca type jack.  and the remote wire i have isnt set up for something like that. is that even where i plug the wire in at? if so, which hole do i choose? Also, where it has the right and left speaker channels, where u plug the speaker wire in at, it of course has the 2 rights and 2 lefts. but what stumps me is along with those there is another jack where u can put a speaker wire in that isnt titled any thing,  it doesnt say postive or negative either.   I do not have a manual for this amp that is why im am here looking for help.  i hope you guys can help.