Difference between "recently" and "lately"

I have posted a topic using this sentence:

I have picked some fictions to read lately.

RegDwight edited this sentence to:

I have recently picked up several works of fiction and begun to read them.

What is the difference between lately and recently in this context, and why is it more appropriate to use recently?

I think the difference is that lately has more of a continuous or repetitive meaning (similar to the perfect aspect/tense), and doesn't work well for individual events, while recently can be used for both.

For example,

• "I went to the library lately" is ungrammatical, but "I've been going to the library a lot lately" is fine. ("I went to the library recently" and "I've been going to the library a lot recently" are also both fine.)
• "I haven't seen her lately" and "I haven't seen her recently" are both fine.
• "Have you been to the movies lately?" and `Have you been to the movies recently?" are both fine.

I'm hoping someone else can elaborate on this, though.

As @grautur pointed out, "lately" is not used to describe a single recent event, when the sentence is affirming an action, so your first example sentence is an incorrect usage. One reason why its meaning is restricted may be that it is, as a word, less common.

To expound:

"Recently" can refer to any event or events in the near past.

"Lately" can refer to any recurring event in the near past, or to a single event when one is saying that it did not happen in the near past.

For example, the following example is incorrect, because it is saying that the event did happen in the near past:

I went to the library lately.

"Recently" is the only word to use here. However, if you did not go to the library, and want to say so, you have a choice between "lately" and "recently" (also remembering that haven't gone instead of didn't go flows better here):

I haven't gone to the library recently.

I haven't gone to the library lately.