Hi Matt!
I was using this site a lot in the beginning. It's pretty good, as it dynamically generates task sheets including solutions for the kana-romajis
Or if you like you can actually use google translate for this as well. It not ontly translates the sentence to english but also converts the kanji and kanas to romaji.
Here is a demo link which converts こんばんは
https://translate.google.com/#auto/en/%E3%81%93%E3%82%93%E3%81%B0%E3%82%93%E3%81%AF