If I want to plug into a DJ's soundboard and he
has 1/4" out, would this most likely be
a single 1/4" stereo? Or more likely would there
be two 1/4" mono plugs? Trying to figure
out what connectors to get for my kit.

My goal is always to get a true 50/50 L/R mix from the board, post-equalization, post-fade and post-mute. I take this input into my right channel and a room ambience mic into the left.

Sometimes there is one jack that will provide that to me. For instance, the balanced MONO OUT (not Monitor Out) on popular Mackie boards. It's often available, since it's usually the balanced Left and Right Main outs that are used to feed the loudspeaker amplifier. The MONO OUT is a 1/4" TRS (stereo) jack, because a stereo jack is required to handle a balanced mono signal. For this I have a one foot long 1/4" TRS to 3-pin male XLR adapter.

But often there are record out jacks, for instance unbalanced left and right RCA jacks. In this case I use two RCA to 1/4" TS adapters and plug them into the two 1/4" jacks on a passive direct box. The ouput from the direct box is then a balanced 3-pin XLR male jack carrying my desired mono mix.

I have two AT8202 in line attenuators in my kit so I can employ from zero to -60 dB attentuation as needed.

I stay away from AUX SENDS because they would have to be set up for me, which is more trouble than I want to impose (and more trouble than a videographer is worth to most sound guys ;>] ).

You can download a typical illustrated instruction manual in PDF form at Mackie's great website. I got one for the CR1602. I also got one from Electro Voice for the BK-42 board in use at my high school.