"I am reading books."
Translation:Je lis des livres.
No, it would not be appropriate. For comparison, it would be like saying "I am read books" in English. So definitely not that sentence. There's also not really another way of doing what you want, since French participles (their equivalent of the "-ing" ending) just don't work this way--they can't be put into those places in sentences. "Je lis des livres" is the correct translation of both "I read books" and "I am reading books." There are other workarounds when one needs to distinguish between these cases, but in general the context is enough to tell.
Would it be inappropriate to say "Je suis lis des livres" in this context?
In English, to mean that an action is in progress at the time you speak, you use the continuous verbal form, ie verb BE + action verb in the gerund form (-ing). o he is eating means he currently eats
In French, this verbal form does not exist (directly translated “il est mangeant” is incorrect). Therefore, you can translate either “il mange” or “il est en train de manger”, where the construction verb être + en train de + infinitive correctly expresses the English continuous form.