Hi Sandy,
Welcome to TechSoup. Glad to have you join us!
You should know that translation software (aka "machine translation") won't be perfect in no matter what language you want to translate to. The most accurate translation remains human-performed translation, which is the only way to guarantee a 100% correct output of your English to Spanish newsletter and website. I'm telling you this because I want you to know what to expect with translation software, namely that you'll never get fully accurate translations. However you can still make use of translation software if you want to obtain "on the fly" draft-quality translations of your materials. Sometimes you don't have the people needed to do the translating, so having the software do it for you can at least get you started with the process which then makes it easier for a person to "finalize".
Before you jump into buying any software, there are a number of free online translation tools that you might want to consider for translating any document for you (newsletters and even entire websites) within a few seconds. Here are a few free tools I recommend:
- Google Translate
- SYSTRANet.com (by SYSTRAN)
- Yahoo! Babel Fish
Give these tools a go and see what you think. Often they'll do a decent job, but you should expect some phrases and words to be lost and nonsensical in the translation process. That's why you'll ultimately need to have the outputted text looked at by a human being -- to render it 100% accurate by someone knowledgeable in that language. I myself used Google Translate yesterday to get an English-written site that I developed translated into French. Google Translate did a fairly decent job rendering the French output. But like all machine translation it's far from perfect, which is why I'm having someone I can trust finalize the French version of the site.
Hope this helps.
Yann