This is a pretty decent online translator:
http://tengwar.art.pl/tengwar/ott/start.php?l=en
You can either use the PNG option or download one of the required fonts here:
http://www.acondia.com/fonts/tengwar/index.html
(Don't use the fonts without a transcriber though, they have a different keyboard mapping than most fonts. The fonts that are not in the transcriber's list but have Dan Smith's layout (see the descriptions) work with the transcriber results, too, just use the Tengwar output format and copy into Word (or similar))
This transcriber usually doesn't note silent e's though. It's spelling is mostly orthographic.
The mode you should use is English mode, which can be checked with these sites:
http://www.acondia.com/fonts/tengwar/info/english.htm
http://at.mansbjorkman.net/teng_general_english.htm
If you want any additional help, or someone to check your results, feel free to send me a message.