All of these provide a dictionary which tells you whether a phrasal is separable or inseparable.
http://www.englishpage.com/prepositions/phrasaldictionary.html
Gives pretty easy explanation about the grammar rules of phrasals.
Glossary of English Phrasal Verbs: Index
http://www.usingenglish.com/reference/phrasal-verbs/
http://www.phrasalverbdemon.com/
Has good explanation about particles (including prepositions) under "Particles."