There's not a huge amount of info on burning DL Video DVDs, so with the focus on quality & in case it helps...
Burning Dual Layer Video DVDs is a bit complicated... Ideally the Layer Break [the point where the player starts reading the 2nd layer] is at the mid-point of all the data you're burning, AND, ideally it's at a point where you won't notice a slight pause, usually a scene in your video when/where there's a minimum of anything happening with video or audio. Usually the layer break also comes in the middle of the movie you're burning to your video DVD -- it's nice when you have 2 title videos [e.g. TV episodes] on a disc so you can break in between them, but as dual layer blanks are more expensive, people usually only use them for longer movies. The layer break happens at a cell you choose, DVD title videos have one or more cells, cells can only be at I frames [key frames] in your mpg2 video, & you might think of cells as a sort of bookmark. Chapters can only occur at cells, but cells do not have to be chapters. Most DVD authoring apps let you set chapters, but not just cells, which can be a problem since the best layer breaks often make for a [sometimes very] poor chapter -- you don't want to jump to a part of the movie where nothing's happening. Here's how I get around the issues...
I start by creating [not burning] the DVD as if it was going on a single layer disc, setting chapters at the beginning of scenes of interest, creating scene menus based on those chapters, & when everything's done I'll have the software create the DVD files & layout in a VIDEO_TS folder on the hard drive. Once I'm sure it works [I play it in PowerDVD], I'll open that DVD on my hard drive in PgcEdit, going through the File menu to have it create an ISO -- because it won't fit on a single layer disc, that opens a dialog window for setting the layer break -- I look at the ideal split point, compare that to the chapters/cells listed, & for this example I'll say the ideal place for a layer break is between chapters 9 & 10. Closing PgcEdit I'll reopen the project in my DVD authoring software, find the best spot for a layer break between chapters 9 & 10, add a new chapter there [but not to the scene menus or anything], & recreate the DVD on my hard drive. Now when I open the DVD in PgcEdit I'll go to the title on the left hand side, double click it to bring up the editing window, delete chapter [but not cell] #10, remove the last chapter # so the total number of chapters is the same as the original layout, & click OK, then create a dual layer ISO, selecting the cell [minus the chapter] I added for the layer break. When I burn that ISO ImgBurn asks me to confirm that's where I want the layer break, & that's basically it, from that point on just burning the disc like any ISO.
A bonus tip...
Say you've recorded a TV show or movie in DVD spec, mpg2 video, & want to 1) create a video DVD, & 2) cut out the commercials without re-encoding or any real editing... I've done this loads of times with video from my DVD recorder. First you create the DVD layout as above, ignoring any of the commercials you want to remove, but unless it's going to be a dual layer burn, don't render it to your hard drive just yet. Now go back & make sure there's a chapter before & after each commercial (&/or portion you want to cut), & once those are in place, render the DVD to your hard drive. Open the DVD in PgcEdit, only instead of just removing the chapters you want to remove all the *before commercial* cells themselves. Since a DVD is really just a playlist including the cells to play for a given video, removing the cells with just commercials means the player will skip right over them.
Is it fast? Yes... it's the fastest method of cutting commercials I'm aware of, though some software will automagically skip commercials when viewing/recording, which would be faster yet. Is it fool proof? No... Cells can only happen at I frames, so you might not always get the exact frame you want -- players are also seldom perfect. This is pretty much the same thing that happens when you edit recorded video in a DVD Recorder, only instead of adding cells just where you need them, a DVD Recorder would just insert an awful lot of extra cells when it recorded the video, when you edit picking the closest ones [Pinnacle software last I looked always added a lot of extra cells too].