a good site is http://www.forvo.com/ just type in the word you want, search it, then click on one of the results to hear an iranian who has uploaded their pronounciation of the word say it. That's what I do when I'm not sure of a diacritic. But if all else fails just pm me or I could give you my email, just send me the list of words you need diacritics to and I'll give you the full pronounciation. Because honestly there are not many flash cards beyond extreme beginner words that have diacritics. Not sure why..
I've been working through the lessons on EasyPersian(http://www.easypersian.com), I find them good. I've been adding the new words in each lesson to StudyBlue(http://www.studyblue.com) and studying the flashcards on my phone while on the bus, before going asleep etc. It's a good way of building vocabulary. I've found that it's best to add the new vocabulary and study them for a day or two before going back to write the exercise sentences so that there's less need to refer to the vocabulary. I usually do have to refer to the vocabulary to check spellings but I can fairly accurately guess the spelling in most cases now.
I've also been using Pimsleur's Farsi which is quite good for speaking along to. Having tried Pimsleur's Urdu in the past I find it helpful to have studied the script and written lessons at easy persian, it's easier to distinguish words and elements of grammar. I try to write out what I hear now. I've added persian to my languages on the pc and got persian character stickers to stick to the keyboard.
I've gotten lazy though. I need to find someone who speaks the language to practice with and there are no such people locally.
Harry Potter and The Prisoner of Azkaban has been translated into Persian, so you could read it alongside the English version. It is available in paperback from Amazon and I found it to be a very readable translation. https://www.amazon.com/Harry-Potter-Prisoner-Azkaban-Persian/dp/9645757010
As far as the basic Persian vocabulary is concerned, you could use the following apps to learn (or relearn) some Persian words and phrases from scratch
Beginner Persian https://play.google.com/store/apps/details?id=com.shex.beginnerpersian
StartFromZero_Persian https://play.google.com/store/apps/details?id=com.shex.startfromzero_persian