Wiring DVD, LCD, and FM Modulator?

Hi every, I am a newbie and this is my first post.  I hope you guys can be easy on me since I am not sure about wirings for DVD, LCD and FM modulator. 

1) Can I attach the positive wires on the DVD player and the LCD(The DVD can be powered by the 12V AC cigarette lighter, but I want to have a clean look) , then connect these wires to the positive 12+ ignition wire, and then ground the 2 negative wires on the DVD and LCD?    If not, what can I do?

2) Does a FM modulator need power?  If so, can I do what I said on #1? If not, please help me.

I hope some of you guys can help me here....Thank You very much!

1) Attach the 12 volts power wires to a spare slot in the fuse box or run off the ignition wires from the cylinder. Ground you will need to find a solid and clean metal surface.

2 ) Yes, the FM modulator requires power and ground. Wire the same as above

Thanks a lot Jeff!!!

Two more quick questions:

1) Do I shove the 12 volts wires separately (DVD, LCD, FM Mod.) or can I attach all of them together then shove them into one fuse slot?

2) How much 'pc' fuse do I need for DVD, LCD and the Fm modulator?

Thanks a lot!! You guys are very helpful!!

The FM Modulator should only take 1.5Ampt to 2.0 amps.  Look at your SPECIFICATIONS area of the manuals to see what the MAX watts are for each device.  The INPUT wattage or amps will be what you are looking for, total that all up, and add 5A more to that, and use the CLOSEEST to that value fuse.  That's my opinion.

Usually, just splice them B+ lines all into the same fuse.  Unless you want to be sure they POWER OFF when the key is off, use a relay, or area where power is on when the key and/or engine is on.  I got lucky where I put the wire, there is only power to it when the key is on, and engine running.

I have two empty spots in my inside fuse block, one was for ABS, and I do not have it.  I put a wire into that, and shoved a fuse in top of the wire.  

When you do this, make sure you put the wire on the COLS side, then when the fuse it in, you get power to that side, so so you blow the fuse instead of something else.

I put a wire on what I thought was the supply for my seat motor, or something, and put an AMP on it.  The amp acted like it had a bad ground, when I did some changes, and got a bad hum, like a low bass tone.  It drew too much current, and popped something, because the amp stopped working.  I moved the B+ to a new location, and it works.  I have no Idea what I took out, everything works in the car.  The seatbelt light flashed now, when it used to be SOLID, so maybe part of that circuit got toasted.  ALL my fuses are ok, none were blown, so I do not know what happened, strange huh?