I've been enjoying the first two weeks of the new F1 season and have already gotten used to the rather strange looking cars. The reason the cars look different (and possibly the reason the races have been so interesting) is that this year the technical regulations have been dramatically altered. Basically the aerodynamic aspects of the car now produce less down-force, which has meant the re-introduction of slick tyres so the cars have enough grip to stay on the track, but should produce less turbulence allowing for closer and more interesting racing. Following these technical changes is a challenge but fortunately there is help.
The official F1 website has a technical section. It is divided by year and race (as well as a general category for new things introduced during testing etc.) and each interesting change to a car is highlighted with a technical drawing and explanatory text.
The main issue so far this year has been the diffusers and they are covered in great detail. There are pages on the three cars with interesting diffusers (Williams -- here and here, Brawn and Toyota) as well as on some of those who have taken a very literal interpretation (Ferrari and McLaren) and some discussion of the merits of both approaches.