Hey I just took the DAT this past saturday and I got a 24 on Reading. The passages were relatively easy to read and they were all science based. No humanities or social sciences like on the MCAT. All I did for this section was quickly read each paragraph and write down one or two words that were unique to that paragraph. I call these 'buzzwords' because sure enough they show up in the question stems. If you have the passages numbered, refering back to them takes only a few seconds.
You can practice by getting your hands on exam kracker 1001 passages book. Just do the natural sciences passages.