Thank you for the advice. Yes, it does help. I am a slow learner. I have only just installed Adobe CC and the photos were already on iphoto. In future I will download direct to Lightroom as suggested.
Thank you for the links.
My suggestion is to pick either LR or iPhoto, and not use both. It sounds from the post quoted you might be thinking of importing to LR then to iPhoto.
One of the nuances of iPhoto and Lightroom that many new users miss is that the original images - in your case the RAW files - are never altered. When you edit an image in LR or iPhoto the application keeps a record of those edits in its database. It only applies those edits when you look at the image, or export the image.
For example - if you crop an image and then turn it into a BW photo in LR, if you then access the original image using iPhoto (that is - without exporting it first) you will simply see the original uncropped and unedited RAW file in iPhoto. All of the those edits are 'lost' as far as iPhoto is concerned.
When you use Photoshop as an external editor, iPhoto or LR will usually send it the image with the existing edits noted (in LR you have several options, in fact) and then when you 'Save' in the Photoshop the edited image is then placed next to the original untouched file.
If you access the original RAW files directly with Photoshop (instead of having PS set up as an external editor in iPhoto or LR) you will be editing an image that has none of the edits you have done in LR or iPhoto. Plus - unless you do a 'Save As' in Photoshop you will overwrite the original RAW file... potentially corrupting the database.
So... my suggestion... pick one DAM, and then send the images to Photoshop by linking it as the external editor to that DAM.
Also keep in mind that everything about iPhoto and Lightroom noted above also applies to Aperture. In the case of Aperture and iPhoto you can in fact use two DAMs because they can share a common library.
Luck.