If you take care of that motor it will pretty much last forever. D-series are SOHC Daily Driver champs. B series motors are DOHC engines that come in Integras, CR-V's, some Del Sol's, and 99-00 Civic Si's. The K series is Honda's new DOHC Vtec motor that replaced the B series, which can be found in RSX's, new CR-V's, TSX's, 02-present Civic Si's, and so on..
All of these motors come in a ton of different flavors, you will learn.

For Civics,
DX and CX are the two lowest trim level options. No power anything, lightweight, basic.
LX and EX are the upper trim models, easy.
Si (sport injected) are the sporty model Civics.
EF = 88-91
EG = 92-95
EK = 96-00

90-93 Integra = DA
94-01 Integra = DC

If you want to know anything specific just ask, but someone else answer his tranny question!