For all but the most experienced trial lawyers, there is much to be learned by watching real trials. Next time you're at the courthouse on some routine matter, try dropping in on a trial in progress. Pay attention to the lawyers. What would you think of them if you were on the jury?
It also pays to read trial transcripts from time to time. At most firms, there's a transcript or two available to look at, since trial transcripts are often necessary for prosecuting appeals. Pay attention to how the lawyers handle exhibits and get them admitted into evidence.
For trial transcripts online, check out Famous Trials by Doug Linder. Though most are criminal cases, as opposed to civil, it's fun reading some of the testimony in cases like the O.J. Simpson trial--for example, F. Lee Bailey's cross of Mark Fuhrman.