I've been attempting to read a lot of papers in the past week, and struggling fairly badly. Reading primary literature is hard for two reasons: you need to have enough background knowledge to understand the experiments, and you need practice at parsing the language and form of papers (a nontrivial skill). I've come a long way since high school, when it took me several days to look at all the words in a paper (and I still came out the other end with little understanding of what actually happened)... but I still have an awfully long way to go.
Which is why I love review papers. The literature search is done, the information is chewed-but-not-digested. It's just the right level for an undergrad. (Book chapters can also be good, but seem to be a bit less up to date because the publication cycle is longer.) A review paper is the best way to start a new literature search, or to get the "state of the union" on an interesting area you're not expert in.
<3 people who write review papers