Home-burned DVDs use a chemical process rather than imprinting their data to a solid disc (as commercial DVDs do) so they won't play on all DVD players. But most players made in the past 10 years or so can play home-burneds.
As I say in my books, there are two ways to increase the odds your discs will work:
1) Use a quality disc brand, like Verbatim or Tayo Yuden. Stay away from cheaper brands, particularly Memorex.
2) Never record at faster than 4x, even if the discs are rated for recording at a faster speed.
And, of course, never stick a label on a DVD disc!