I am a Product Manager for an LED lighting company and power conversion (line voltage AC to low voltage DC) is one of the most fundamental engineering issues we face. I am trying to get a better understanding of the basics of power conversion, can anyone recommend a good place to start?

It sounds like you are looking for a textbook more than a cookbook. In that case I recommend "Fundamentals of Power Electronics" by Erickson and Maksimovic (2nd edition). If you do buy it please try to buy a US copy and not an "International Edition" (which are cheaper but the authors don't get the royalties).

Others will offer their favorite books from Ned Mohan, Abe Pressman, or Rashid.

Disclosure, I am a part time student at University of Colorado - Boulder and have taken classes from Maksimovic and Erickson is my thesis advisor.

"Switching Power Supply Design" by Pressman is my go-to text. I know it so well, I don't even need to look at the index or TOC! But I agree with Bob that Erickson and Maksimovic looks very good, too.

I do find Pressman somewhat limited on the simulation side. I have put a lot of his calculations into Excel spreadsheets, which are pretty useful.

Can anyone recommend "Switch-Mode Power Supplies Spice Simulations and Practical Designs" by Christophe Basso?

Don't get into the trap of feeling like you need to make an isolated power converter but do be careful. An ordinary light bulb filament is not isolated from to power line but the whole unit once screwed in does not expose any conductive parts and you will need to keep that insulation isolation or if any heat sinks or other metal is exposed they will need isolation.

Considering some one is needing basics of power conversion and working in the Industry of designing LED driver, I would recommend the latest edition book by Abhram Pressman. Pressmans book and the book by keith billings had good balance of theory and practice. The book by Cristophe Basso is well packed (can be too much for beginner).
For quick understanding of the principles and then getting to practcal aspects, I would recommend Sanjya Maniktala's the A2Z book. The book by Prof Erickson is must read for getting into deeper fundamental, I Read Ned Mohans book during my University days. (Both are Excellent and to some extent complement).
There are many other good books, like to buy them whenever a new book appears. These books and TI/Unitrode seminers are highly recommended along with Ray Ridelys paper over the years. Hoping for the next book from Ridley, I am sure there will be one inspite of all the piracy issues!
For good understanding of specific issues concering say LLC conversion or synchronous rectification, EMI, control loop design etc, best resources are found by combining by gleaning through several Application note and details of Demo board design that are offered by the semiconductor companies.

Practical Design of Power Supplies by Ron Lenk: it is written in plain English and covers all the material in a very comprehensible fashion. It is perfect for those that need to understand power supplies but do not need to understand all the derivations of the equations.

To be more specific, Power Supplies for LED Driving by Steve Winder is more apt for your particular discipline.

Fundamentals of Power Conversion by Erickson and Maksimovic from the University of Colorado at Boulder is the de facto standard textbook on the subject. UCB also offers three courses from the book; after taking them one receives a Certificate in Power Electronics that is well-respected in the industry.

I think we have gone astray. The key words are "Product Manager" and "understanding of the basics of power conversion. He is looking for fundamental/practical books and not university-level books. Martin himself and on behalf of the people working for him most likely come from different backgrounds and need a primer to boost their short-term knowledge level on the subject.
There are three authors that meet this need, in my opinion: Dr Ray Riddley, Ron Lenk, Abraham Pressman and myself. All bring a, sometimes, confusing subject down to a level which can be understood by non-power engineers.
Martin, I would recommend going to Amazon and looking each author/book up and reading the short sections provided, and the reviews. You can get an idea which author has the most desirable writing style, level and content that works best for you.