So I've been trying to make an intro for my youtube channel and I've made it and rendered it but I don't know what to do after I'm done rendering. Can someone help me please.
Saving a Still Image
(Assuming you have already rendered your image - if you haven't yet, do Render > Render Image)
From the UV/Image Editor menu, choose Image > Save As Image
You will be presented with a screen prompting you to choose the file path where you want your image to be saved.
If you ever see the file path field turn red it means a file with that name exists, and saving with that name will overwrite the existing one.
There are some options for file format and color information on the bottom left.
Then press the Save As Image button in the upper right.
Clicking the "plus" button or pressing + = will increment your file name by one number.
Note that Blender can also be set to write still renders to disk, like it does with animations.
Specify a file path in the Render context. Use PNG for rendering individual image frames, or a video container format such as MOV if you want a single video file.
Specify the frame range.
Choose Render > Render Animation or press the Animation button.
But that's not a real Blender related question if you wanted only this as an answer...
Make sure, your render is in one of the supported YouTube file formats, namely .MOV, .MPEG4, .MP4, .AVI, .WMV, .MPEGPS, .FLV, 3GPP or WebM. Only some of them are supported by Blender through the intenally used ffmpeg. It depends on your system and how Blender was compiled, but there already are other questions about this topic...
Consider using the recommended upload encoding settings: MP4 as a Container (without Edit lists), AAC-LC as an audio Codec with Stereo or Stereo+ 5.1 and a sample rate of 96 or 48 kHz, H.264 as video codec*, if possible the same framerate as it was recorded, deinterlace your footage if possible, use a 5Mbps Video Bitrate for 720p or 8Mbps for 1080p for standard framerates (24-30) or multiply by 1.5 for high framerates (48-60) and if possible use a 16:9 aspect ratio. For Audio use 384 kbps for stereo or 128 for mono. Not everything that YouTube recommends can be set up in Blender properly, though.
*For the H.264 video codec use:
Progressive scan (no interlacing), High Profile, 2 consecutive B frames, Closed GOP (GOP of half the frame rate), CABAC, Variable bitrate (No bitrate limit required, though we offer recommended bit rates below for reference), Chroma subsampling: 4:2:0.
To give you a few more details of what to setup in Blender for example for a 25 fps 720p video:
Hit Render Animation (CtrlF12), wait for it to finish and the upload the generated upload.mp4 next to your blend file to YouTube as described above.