Which of these books I should read first?

[Tara]

I recently bought these books, and I'm not so sure which one i should start first. The books I got are Clockwork Angel (first book in The Infernal Devices), Delirium & Pandemonium, & The Selection. Each series contains 3 books. They are all trilogies. The third book for The Selection has yet to be released. I want to read a series that has already been completed. So I guess that rules The Selection out. But I cannot decide between starting The Infernal Devices or the Delirium Trilogy. I don't have the second or final book in the Infernal Devices Trilogy. And I don't have the final book in the Delirium Trilogy. I don't know when I will be able to purchase the remaining books. Please help? I cannot decide! I've heard so many great reviews from both trilogies!

[Brenda]

I have not read either of these trilogies, but do know that the INFERNAL DEVICES has been really popular at the library I work at.