What's the best resource for learning SEM/PPC bid/budget management of 100,000 to 1,000,000 keyword AdWords accounts?

I can discuss having done indepth research before we select Marin software

Depending upon what aspect of AdWords you want to automate, you can look at various tools. As Megumi suggested, Marin is a good option for bid management. You can have a look at Optmyzr (optmyzr.com) to automate account management activities. Cyfe is another option to automate reporting and building dashboards.

Technically you can bid on competitors. Take for example Autotrader who bids for keywords such as Honda, Ford, etc. But the best advice is actually here http://searchengineland.com/the-complete-guide-to-bidding-on-competitor-brand-names-trademarked-terms-118576

Here is how I'd suggest you learn SEM: #1 - Open a Google Adwords Account (You can search for free credit / promo codes) online and play around with it. #2 - Review all of Google's training material: https://support.google.com/adwords/?hl=en&page=examstudy.cs#topic=3119071 #3 - When you finish Google's training materials, then read about Adwords on the web. Here is one good resource and you can Google for more: http://www.wordstream.com/adwords-for-dummies #4 - Sign up for an affiliate network (e.g. Commission Junction or Linkshare) and use your free credit to promote another company's offer. #5 - Once you feel comfortable with Adwords, consider building out your own Lead Gen websites or selling leads to existing affiliate networks (e.g. Motive Interactive or Integrate.com) #6 - If you'd like to learn from someone else, find an entry-level job at an agency: http://www.indeed.com/q-PPC-entry-level-jobs.html #7 - Another good way to get good at PPC if you work in an in-house marketing role is to hire someone to audit or manage your own account for a period of time so you can learn how they think and what they do. #8 - One word of caution: Google takes a minute to learn and a lifetime to master. Their default settings make it very easy to waste a lot of money so really make sure you know what you are doing before you spend too much money.

It all depends on whether they are all selling the same thing to the same persona. If yes, then combine all the campaigns into one adwords account, which feeds into one analytics account. That way they can get feedback on the effectiveness of different keywords, ads, etc. more quickly (because there will be more data, from all the different websites, all in one place, for a particular keyword). If they are each selling different things, or to different personas, then don't combine their accounts, because it will just make things confusing and not useful from an analysis perspective.