well, that was certainly a vague posting, but i'll do my best to advise on my limited knowledge:
the differences that should be noted when shopping for a dvd burner are:
brand: who makes the drive? are they reputable?
dual layer or not: single layer dvds can store 4.7gb, dual layer dvds can store 8.5gb, but are more expensive than single layer blank dvds.
+/- : there's not much difference between plus and minus. they are both very easy to buy in stores, and most current burners can use both kinds. from webopedia.com:
DVD-R is supported by Panasonic, Toshiba, Apple Computer, Hitachi, NEC, Pioneer, Samsung and Sharp.
DVD+R formats are supported by Philips, Sony, Hewlett-Packard, Dell, Ricoh, Yamaha and others.
speed: 16x? 8x? but note that the dvd burning speed is different than the dvd reading speed, which is different than the cd writing speed, and the cd-rom reading speed (example: 2.4x DVD+R DL (Double Layer), 16x DVD+R, 4x DVD+RW, 8x DVD-R, 4x DVD-RW, 48x CD-R, 32x CD-RW)
interface: this is usually very obvious, but you can buy internal dvd burners, and external dvd burners. external dvd burners are more expensive because you can hook them up to laptops and desktops, internal burners can only be installed on desktop computers with extra space for a drive.
i think that's about it. as for recommendations, i don't really have any. my dvd burner came with my computer, and i don't use it too often, so, anyone else have recommendations?