There are several websites on the subject here are some examples --
food list (this often varies - but basically fruit & veggies are alkaline)
http://www.phmiracleliving.com/alkaline-foods.htm

an interesting water:evamore.com

acid balancing supplements:
http://www.enzymedica.com/products/pH_Basic
Books are listed on the bottom. The Young & Cousins books are very well known. phmiracleliving.com is Young's website

I think this a a critical and overlooked topic in the cf clinics. You can buy Ph paper at the drug store. Test several times on several days and you'll get an idea of how you are doing. Basically you want to see some alkaline readings - so you know you have alkaline reserves (not too acidic)You can also find more details about how/procedure for testing on the web. (Also be aware that delayed release enzymes can be released in an alkaline environment so keep that in mind... if trying to boost alkaline level, maybe do away from regular meals?...I am still working on the best strategy myself...)