Seconded, for a lot of reasons including:
1. It works with a huge variety of lenses (Nikon, Canon, etc. via adapters).
2. It has continuous video recording (most dSLR's max out at 30 minutes per clip).
3. It has 4K UltraHD recording, which can be downsampled to 1080p for a super high-quality HD picture.
4. It's small. Having a compact camera is nice.
5. It has advanced film tools like color bars, zebra, etc., can use speed boosters like the ones from Metabones, doesn't overheat like a lot of the other dSLR's do, etc. That means it can grow with you as you gain knowledge & experience.
Body is $1500 on Amazon:
http://www.amazon.com/Panasonic-DMC-...dp/B00I9GYG8O/
OP, if you want video blog-style footage, just buy a cheap prime lens like a Canon 50mm f/1.8:
http://www.amazon.com/Canon-50mm-1-8.../dp/B00007E7JU
It will be manual-focus only and you will need an adapter:
http://www.amazon.com/Fotodiox-Mount...dp/B003EAXT5G/
You can use an external monitor via HDMI for monitoring (to see yourself). There are lots of cheap 5", 7", and 9" HDMI monitors available (do an eBay search for "Lilliput", or you could just spring for like a $99 20" LED screen. Alternatively, you can also monitor via wifi on your smartphone or tablet:
http://cheesycam.com/panasonic-gh4-can-simultaneously-output-hdmi-with-image-app-wifi-remote/
One other thing you'll need is lighting. I like LED light panels, which run about $150 for a cheap 500-LED unit. Or you can get a lighting kit, either a couple of umbrellas with bulbs for $50, or a bit of a nicer setup like this:
http://www.amazon.com/Linco-Lincosto...dp/B00IRXMH0S/
As far as audio goes, you do
not want a shotgun mic. There's a common misconception in audio recording that a shotgun mic works like a zoom lens - it doesn't. Audio is simple: place the microphone within 12" of the speaker's mouth. Either on a boom mic above their head, or on a clip-on lavalier mic on their shirt collar. It's not like a camera lens, where you can zoom in on a subject & filter everything else out - if you use a shotgun mic 6 feet away, it's going to pick up computer fan noise, HVAC noise, room noise, your cat, everything.
The easiest way is to do audio is with a lav mic. That's a whole different discussion, but the bottom line is that you need to invest in a quality audio setup if you want to look professional. Most Youtube videos look amateurish because they have crap audio. The GH4 has a 1-volt 3.5mm jack, so you can run certain mics right on the camera:
http://www.amazon.com/Rode-LAVALIER-...dp/B003Z8OUUA/
Just needs an adapter:
http://www.amazon.com/Rode-MiCon-2-C...dp/B003ZDVKC6/
It all depends on your budget. With good lighting, you can get great-quality footage on even an iPhone. If you have a tight budget, I'd suggest picking up a 5th-generation iPod Touch (1080p video) and a Rode SmartLav. The iPod comes in 16, 32, and 64gb sizes: ($220, $250, & $320 respectively)
http://www.apple.com/ipod-touch/specs.html
The mic is $80:
http://www.amazon.com/Rode-smartLav-...dp/B00EO4A7L0/
A tripod adapter is $4:
http://www.amazon.com/Octopus-Portab...dp/B007NFI656/
That includes a desktop tripod - you can just buy a cheap $30 tripod to put the clamp on:
http://www.amazon.com/Professional-P...dp/B002ONSZPI/
The Filmic Pro app has a lot of video controls for only a few bucks:
https://itunes.apple.com/us/app/filmic-pro/id436577167?mt=8
Plus, you can edit & publish right from the iPod, which is super convenient. All depends on how much you want to spend. At minimum, this is what I would buy:
1. A good-quality camera
2. A tripod to stabilize the video picture
3. A clip-on lav mic (with a long cord)
4. A basic lighting setup
For $500, you can get a killer iPod-based setup. That may sound stupid, but the picture & sound quality of today's portable devices is incredible. For $2000, you can get a really serious system. Although if your budget is even tighter than that, you can get away with a couple of desk lamps for lighting, a 1080p webcam, and a cheap lav mic for under $100:
http://www.amazon.com/Logitech-Webca...dp/B006JH8T3S/
http://www.amazon.com/Audio-Technica...dp/B002HJ9PTO/
A lot of people like to shoot on GoPro cameras too...they're small & can be stuck anywhere, which makes them convenient. There's aftermarket software for removing the fisheye effect as well. Lots of options. I guess the first question is: OP, what's your budget?