You are not very specific about what's difficult about burning to the DVD and playing on a DVD player. Most consumer DVD players will not playback MPEG4.
Standard Video DVDs have a very specific layout. The disc itself needs to be recorded in UDF format (which is a variation of the ISO9660 format of CD-ROMs). The disc must have a VIDEO_TS ("video title set") folder at the top level (there can also be an AUDIO_TS folder, but on DVD Video it generally doesn't have any data in it). The VIDEO_TS folder must have a collection of .IFO (title information), .VOB (video object), and .BUP (.IFO file backup) files. There must be one VIDEO_VTS.VOB, VIDEO_VTS.IFO, and VIDEO_VTS.BUP file for the disk VGM (disc title) menu, then a series of VTS_* files with the titles themselves on them.
The .VOB files are actually multiple video (one main, the rest are alternate "angles"), audio (one or more languages, for instance), and subtitle streams multiplexed together. The video must be encoded as MPEG-2 at 9.8 Mbps or less, or MPEG-1 at 1.856 MBps or less. Permitted resolutions are 720x480, 704x480, 352x480, or 352x240 pixels at 29.97 frames per second for NTSC video (used in the USA and Canada), and 720x576, 704x576, 352x576, or 352x288 pixels at 25 frame per second for PAL/SECAM (used in the rest of the world). There are also some specific requirements on the frequency of I, P, and B-frames in the video streams, etc.
The audio may be encoded as PCM, DTS, MP2, or AC3 -- and there are of course requirements as to the frequencies, number of channels, and bitrates permitted for each.
The .IFO files contain information about the number of streams in the VOB, where they are, the chapter information, etc.
When you use iDVD to create and burn a DVD, it takes care of the whole business of encoding and formatting the DVD for you to be compliant with the requirements for DVD Video. You just tell it what you want, and it encodes the video, writes the IFO data, and builds the DVD for you.
When burning a DVD, keep in mind that slower burns result in more reliable disks, so burn the disk at the slowest possible speed. If you are going to burn several copies, and you have disk space, it's handy to simply create a DVD image file that you can burn later with Disk Utility.
Also, keep in mind, not all set-top DVD players handle recordable media (particularly dual-layer and read/write media) very well. Some brands of recordable media are also better than others. Older DVD player may not be able to read recordable DVDs at all. Many players handle DVD+R better than DVD-R, though older players might prefer DVD-R disks.