Fill Any PDF Form is a very useful site. If you are like me, you hate when someone sends you an electronic form that has to be printed out to be filled out or signed. Fill Any PDF Form fixes this situation.
Will Fill Any PDF you can fill out, sign, and send forms all from the site. You can use any PDF form (or MS Word) even if it wasn't set up to be filled out online. You can invite others to fill out forms and track the results so you don't need to send the forms out.
The free plan is actually very full featured and easy to use.
I Love PDF - merge or split PDF files
Lots of PDF resources - print, markup, convert and more