Ramses of Spanish-Only.com is a man who likes his sentences. While I tend to butt heads with him on grammar-learning methods, I do agree with him wholly on the value of sentences in language learning. I use them (although not solely, as he does) to learn vocab, and finding good sentences can be something of a challenge.
Well, Ramses has made it a little easier for you Spanish learners with this database of Spanish sentences and their English translations (hat tip: Babelhut).
There's nothing quite like context to help you learn a language, whether for vocab or catching grammatical rules in practice, and sentences give you bite-size chunks of context good for just that. They won't be quite as useful for you as they were for Ramses (who got them from their original context), but the database can save you some work if you're looking for a ton of sentences that already have translations conveniently located nearby.
My one request at this point is a way to easily incorporate these into a spaced-repetition system. Currently, as far as I can tell, you'd have to pluck out the sentences one by one, but hopefully that is something that will change over time as it continues to be a work in progress.