What is the best software for accurately converting hundreds of documents at the same time from one format to another. Like doc, txt, rtf, pdf to epub and vice versa?

OpenOffice.org/LibreOffice would be ideal. There are many threads on their forums about bulk conversions and ePub is supported by an extension. You may have to do some macros to do it in bulk.

Btw, would it be better to have active screen or e-ink screen?

So, something like this-


vs




I can't decide, the colored one obviously looks better but since e-ink is not an active screen the battery can last for at least a week of intense reading before recharging.

I'd much rather read on non-backlit e-ink, especially with default colors (black on light/white). If you're going to read a lot, try a few alternatives before buying. Your reading comfort is paramount.
Other than that, there's battery life as you mentioned but also capability: a color screen can display properly stuff e-ink can not.

Calibre is often recommended for managing ebooks.

+1 for e-ink. Makes you forget that you're staring into a screen.

Just one solution: http://calibre-ebook.com

Open source. No cost. Nearly all formats. I couldn't find anything better fpr managing your ebooks.

I've used Calibre for format changes. Fairly straighforward. Haven't used it in a while, so don't know if there is a batch function.

On the other hand you would need to use an external light source for e-ink, are there active screens now that are really easy on the eyes, because I now read from an old laptop so I know what you mean.

What, just like not being able to read a newspaper in a pitch-black room? How retro...

I think Calibre has a batch function, but I'm not sure whether that isn't just unidirectional.

Wouldn't active screen be far more ecological? Also in many situations it is hard to find adequate external lighting. It just feels gimped and awkward that way.
I guess the best solution would be either really advanced active screen or e-ink with back/frame lighting.

There are quite a few e-ink displays with active lighting. Kindle paperwhite, etc.

My kindle wallet has an LED built in, which draws power straight from the device. I hardly ever use it though, as I'm not too fond of reading in the dark.

This is the only one I could find with lighting.

It looks amazing(watch the video), sadly it is not available in my country.

The Nook isn't exactly mindblowing.

If you want lighting, than you have to swallow the Amazon-Toad or take a look at the Kobo Glo http://www.kobo.com/koboglo.

The Glo has given the Kindle a run in those reviews i saw. And: You are not caged in by Amazon DRM stuff as the only accepted ebook format.

Honorable mention: Every Sony reader, they tend to be a little pricy, but they deliver.

Newish Sony readers are popular (I wasn't able to find a used T2 for more than 25% off the price of a new one).
But Sony decided not to integrate lighting and I agree with their decision. It seems they do however offer some kind of cover featuring a little lamp. I've not use for it.
When I want to read at night in a place that's not already lit, I typically switch on my 20W lamp. I am not overly concerned about the ecological impact of this type of lightbulb.

we have a nook touch without back light, its nice and light and easy to read. now im waiting for color e-ink to come down in price (I want a reader with a back light this time tho).