The capacity of a blank DVD is about 4.37gb of actual data (nominally 4.7).
The amount of video measured by time that can fit onto a blank DVD depends on several different factors. First considerations are the codecs used in the video and audio. DVD-video uses mpeg2 video codec and several different choices of audio. Normally you see AC3 or LPCM, though LPCM uses a lot more room and is less common.
Other types of video use different codecs, with Xvid and mp3 being common a few years ago, and now H264 and AAC or AC3 audio dominating.
So, I have to ask, are you talking about DVD-video only?
A second thing to consider is bitrate. All types of video can vary the amount of bitrate used in making a particular video. Higher bitrates tend to give better quality results, but higher bitrates also produce larger file sizes. So there is a balancing act between bitrate, running time of the video, desired file size, expected visual quality and the type of video codec used. Mpeg2 is not particularly efficient in compression. Therefore, to achieve a certain level of acceptable quality, you have to use fairly high bitrates. And so, DVD-video tends to come in large file sizes. A general rule of thumb is not to put more than 2 1/2 hours of DVD-video on a single layer blank DVD. You can put more, but visual quality will suffer. I prefer to limit DVD-video to 2hrs on a single layer DVD.
Xvid can compress a movie much more efficiently. An hour of Xvid video can be done in about 700mb of space in very good quality. So, a two hour movie might take only 1.4gb of space on your 4.3gb blank DVD. You can go smaller, and lower the bitrate, but as you do this, visual quality goes down.
H264 is yet another step in compression, as you can get the same high level of visual quality and use 40-50% less room than Xvid. So, a typical DVD-rip, converted to H264 might only be 800mb in size. Again, you can adjust bitrate and other parameters I haven't mentioned to increase or decrease file size and corresponding visual quality.
So far, I've only been talking about standard definition video. If you switch to high definition video, with its larger resolutions, much of what I've said regarding file sizes is not correct. High definition video takes a lot more room, regardless of which video codec you use, though of course, mpeg2 is the least efficient and H264 the most amongst the commonly used video codecs.
You may have noticed that I haven't said a word about the burning programs. That is because the burning program itself has no part in this. The amount of video you can fit onto a single layer disc depends on the encoding program used. But to answer the question, ImgBurn is the burning program I would most recommend.
If you need DVD-video made from various types of input, I would recommend AVStoDVD as the encoding program. If you want H264 mp4 or mkv files, I would recommend VidCoder or Handbrake.