Hey guelphontlady, I am in this same situation as well- Just got engaged to my amazing American boyfriend and really don't want to mess this up either as the immigration process looks very daunting! I am learning it myself, and we have called immigration and researched and researched. We are getting married when he's up for a visit. The marriage would be legal in both countries, and it wouldn't matter if we had our wedding down there or up here.
The route we are choosing to go is outland, so we can visit his family and not worry about him not being allowed to re-enter Canada until his application is through. It is quicker than inland by quite a bit, and he can live with me still via visiting, as with inland. The downside to this is that he can't work during this time, so we will be on one income.
From what I understand, if he went with an inland immigration application, he can also send in a work visa application at the same time. But applying inland takes longer, and he would possibly be unable to leave Canada until its through.
Some tips for you- definitely send those engagement and wedding pictures (loose, not in an album or anything), pictures with you two and friends, tickets, families tickets from travelling up for the wedding- because if it was a fake marriage, why would his family travel all the way to canada for it? My fiance and I go to some baseball games when we are in the states, so we keep the tickets from those. We keep brochures, little notes we have written each other and cards, and our premarriage counseling correspondence which shows our beliefs and the work we are willing to put into our marriage. We correspond with the premarriage counselor over email sometimes, so we have a record. To go the extra mile, I am writing a letter about our relationship (he is helping) and stating why I would like him to be with me in Canada. It may be excessive, but no way I'm risking anything!
The checklists that come in the application package are definitely helpful, keep one posted next to your computer and make sure you are not missing anything. And don't stress, it looks intimidating in paper form, but you're definitely not the only couple going through this! It'll be worth it in the end
Jalin