τὸν Ὁμήρου ἀδελὸν παιδεύει.
τοὺς παρὰ τῳ Ὁμὴρω φίλους λόγων τέχνην ἐπαιδεύσας.
τὰ βιβλία τὰ παρὰ τῶν ξένων ἐπαιδευε τοὺς ἐν τῃ ἀγορα ἂνθρωπος, τοὺς Ὁμήρου φίλους.
There's one thing all of these examples have in common that you're missing which will mislead you when trying to translate them. I've bolded the important bits. Take a look at the word order -- all the sentences have an article, and then the noun that it belongs with, with a few other words sandwiched between them.
Do you remember the discussion in Hansen & Quinn about the position of the article relative to nouns? This is a neat trick that Greek does. Instead of simply throwing you a bunch of genitives and datives and accusatives and leaving you to figure out how they all fit together, it (sometimes) uses the article to "group" words that belong together.
Thus, in the second sentence above, you know that παρὰ τῳ Ὁμὴρω is closely connected with (modifies) φίλους rather than, say, λόγων or τέχνην.
These are which friends? -- the ones παρὰ τῳ Ὁμὴρω, at Homer's place.
παιδεύω takes two accusatives: one is the topic being taught, the other is the student. What words are accusative in the sentence? Start there and I think the sentence will begin to make sense.
You have something similar in the next sentence, except at the beginning there's another variation of the way Greek uses the article to group words together: τὰ βιβλία τὰ παρὰ τῶν ξένων
Instead of sticking παρὰ τῶν ξένων between τὰ and βιβλία, it repeats the article another time as a way of giving the reader a heads-up: hey, there are a couple more words coming up that refer to the books! The books -- namely, the ones at the house of the foreigners.
I have one question before saying anything else about this sentence -- does the text read ἂνθρωπος or ἀνθρώπους? Either one would work grammatically, but it does change the meaning of the sentence. ἀνθρώπους is what I wanted to read intuitively. However, with isolated sentences and no context (a typical problem with these exercises) anything is possible.