What do I need to look for in a new Head Unit?

Hi, I am very new to the whole sound system thing but all I know is that I want a good sounding stereo system and I am looking to gain some knowledge. Hopefully yall can help me out. I am planning on building my own system step by step. First I want to get a new Head Unit. Nothing too fancy for example the ones with the GPS or touch screen or anything. Then eventually I want to get new speakers, amplifier and a sub.

I keep on seeing this JBL stock system thing and this might be a dumb question but how do I find out if I have one or not. I honestly don't know if I have a JBL system in my truck. I have a 2008 Double cab Taco, stock HU with a 6 CD changer.

Also as far as a new Head Unit what do I need to look for. I saw somewhere that someone recommended that the CD signal noise be above 100 DB, 2V on the line outs and a low THD% ex under .1%

So far is this guy on the right track? Also what do you suggest in a good Head Unit. And what features or accessories have you seen to be helpful.

 

Price range? There are tons of head units out there most should be good for what you want. I have a Kenwood myself. I've ran Alpine and Pioneer in the past as well and never had an issue with each. As far as features, depends on what type of sources you'll be using. Most at the very least these days have direct ipod control. Can also get one that will play any USB storage device and some have memory card slots. Bluetooth is also popular as well. TONS of options all depends on what you want. Me for example I never listen to CD's so my Kenwood is strictly a multimedia HU and doesn't have a slot for CD's I primarily use satellite radio and ipod or other USB devices.

If you have the JBL you should have a subwoofer between the seats in the back, I think.

 

As far as price range I am looking for anything from $70 to $150. Also yes I do plan on listening to my Ipod most of the time, I almost never listen to CDs anymore.

I found this cool website called www.crutchfield.com. It has been really helpful. So far feature wise I want like I said before the direct ipod control, radio data system, and steering wheel control compatible

And no I do not have a subwoofer of any kind in my truck that I know of

Does anyone else know how to find out if I have a JBL system in my taco?