Nikon D3100 for youtube videos?

Hi, I'm a vlogger/youtuber. I'm sick of using my other crappy camera and I'm looking for an upgrade. I want a camera which will blur my background (preferably) shoot in HD video, and have quite a large shooting area. The storage needs to be compatible with my computer.

What are the best options for the lowest price? I saw the Nikon D3100, what do you think? Will I need an external microphone?

Unfortunately the D3100 has no provision for an external mic. You will have to go to a D7000 or D7100 for that.

Also, check out the Nikon 1 series. They have been gaining in popularity for their great video, and while you will get some here that will dislike them, they are just regurgitating what they heard on the internet.

You can also get a lens, the 10-100mm zoom which is made for cinema as it has a motor-drive zoom for smooth zooming.

The Nikon 1 V series have external mic capability while the J series do not.

This can end up being kind of expensive, but you could end up with a very nice and small package. I have the Nikon V1 (but not the cine lens), and it is really nice for video.

If video is important, then a camcorder is preferred. It is designed to capture video. And audio. Capturing still images is a secondary "convenience feature".

If stills are important, than use a still image capture device. Like a dSLR. Capturing video (and audio is a secondary "convenience feature". For example, if you read the documentation the D3100 you listed, you will find it will overheat when capturing video "for prolonged periods" (about 15 minutes maximum) and stop video capture until it cools down (takes a long time)… Or… Check their built-in (mono) mic and no (or extremely limited) manual audio control. This means for the D3100 using an external audio recording device like a Zoom H2, H2n, H4n and take the extra steps to import and sync the audio when editing… As for a mic jack in the D3100 - you can download and read through the manual. The easiest way to locate it is to see if it is on pages 2 or 3 - or the index at the back.

Basically you can easily end up spending more money and (learning) time you would not spend if you use the right tool for the task.

I'm not saying any dSLR can't capture good video - they can - but they can't be treated like a camcorder. There are workarounds for lots of things that you normally don't need to worry about when using a camcorder… In the $400 price range, the Canon HF R or HF M series have camcorder candidates in your budget range.

The Nikon D3100 is very good.
It does not have a mic jack though.
The audio quality is quite good for a built in mic.
If you want a mic jack get the Nikon D5100, D3200, or the D5200.
These cameras take great video.
You do need to know how to shoot video.
Even if they shoot good video it can look like junk
if you do not know what you are doing.
When shooting video set the camera to manual.
Set the shutter speed to 1/40-1/50 of a sec.
Also set the ISO to 100-800.
That will make your video look even better.
You will be happy with Nikon.
I would avoid Canon.
I had 4 babied Canon cameras just die.
I would be using them and they would just die out of the blue.
I switched to Nikon and I'm problem free.
It will take some time to get good at cinematography.
Just stick with it and have fun!