Ultimately as your photography and editing progress, you will end up with both Lightroom and either PSE or Photoshop. Most professionals use both Lightroom and Photoshop.
Therefore, the question is where is the best place to start - PSE or Lightroom? Unfortunately, there is no correct answer - hense the various suggestions to your post. I now have lightroom and PSE 11, but started with PSE 8 only.
Why start with PSE: PSE is two programs, the Organizer and the Editor. The organizer is a database/catalog for your photos. It allows you to tag photos with locations, events, etc. It has face recognition, geo tagging, and some other nice things such as sorting your photos by calendar, photo shoot, etc. It is a fairly powerful program. There are some very basic editing capabilities that are part of the organizer as well. The Editor is a stripped down version of Photoshop, with a modified UI. For most non-professionals, the PSE Editor is all you would want, and at this point I don't ever see myself progressing beyond PSE and needing the full version of Photoshop. I have been able to take cars, billboards and electric poles out of a landscape photo. I have also swapped heads from a few photos in a large group photo to get everyone smiling. Many of the plug-ins/add-ons that are available for Photoshop are also available for PSE. You could get PSE and be very happy with it for quite some time, and for some folks that is all they ever need.
So, why bother with Lightroom? I found a few downsides to PSE - primarily in the Organizer. The organizer is very much a consumer level product and doesn't scale for an enthusiast or professional. The biggest problem for me was performance. The PSE organizer is not 64-bit or multithreaded (at least that is what I found with version
. I have a large number of photos, and when I tried to really use all the features (face recognition, multiple tags, etc.) it was just way too slow and basically unusable. I read about others with large databases that were fine, and the newer version might be better. Performance was the main reason I went to Lightroom. One other big difference is The PSE Editor is not designed to work well with multiple files at once - for example, changing the white balance on all the photos from a photo shoot. Lightroom is designed to be the heart of a photographer's digital work flow. It can be customized heavily, and you can process a lot of photos more efficiently - from importing photos to printing or posting. Lightroom feels very integrated. Everything flows well. PSE feels a bit cobbled together - especially between the organizer and the editor.
Starting with Lightroom: If I were to do it over again, I would have started out with Lightroom. I outgrew the organizer quite quickly. Lighroom does it all, except for the occasional need to make extensive edits to a photo - at which point, you can launch an external editor from within lightroom (i.e. PSE Editor) and do what you need. I very rarely need to use PSE. You will never grow out of Lightroom. There is nothing in the PSE Organizer that I miss, and I knew the PSE Organizer quite well. Lightroom can import a PSE Organizer catalog, so upgrading from PSE to Lightroom is fairly painless.
So, bottom line - it is up to you where the best place to start is. If you ultimately outgrow the PSE Organizer, moving to Lightroom is fairly straightforward. If you outgrow the PSE Editor, then you need the full Photoshop.