I think title says it all . I have never owned an ebook reader and am planning to get one.

I have read several posts in the forums and i have a slight idea of what my needs may be, still i would like your help.

Having tried to read on my 6" smartphone, i believe i need a bigger screen for reading, it was annoying having to scroll every few seconds because of the small reading surface.

I read almost every night before sleeping, so a screen with light is a plus.
I mostly download content, so sideloading easily is a must.

I have read that android ebook readers have reduced battery time, i would prefer something that lasts longer since i forget to charge my devices quite often.

Easy to use software since i have never had such a device before.

Greek language support would be nice.

Good handling of pdfs, though not mandatory.

The devices i have considered, due to lack of offer in our market, are the Tolino Epos, Inkpad3 and Kobo Forma, and to a lesser extent due to the smaller screen the Aura H2O.
However i can consider every option as long as it can be bought within the EU from a trusted seller, most importantly for the warranty.

Any help is welcome .
First, the E Ink devices do not scroll they page turn. They need to create the full page and don't move pixel by pixel.

Second, a eBook Reader has a 4:3 screen so it holds more data than you might expect when compared to a typical smart phone. See screen sizes@Wiki » in our wiki to figure out what size screen you might need. You can use the dimensions given on the page to cut out a piece of paper the correct size. Cutting a news paper can give you an idea of how much text you can see.

Generally an android device eats batteries due to wifi and background processes. If you manage this it can do ok on battery life. E Ink@Wiki » screens create the image and no power is used to maintain the image unless the front light@Wiki » is on. See our wiki for how this works. For background you might want to look a the Category:EBook_fundamentals@Wiki » for a selection of basic eBook data.

Good luck on your quest.
Dale
Ereader screen size comparison video:
https://www.youtube.com/watch?v=Ms3wUsuxP7Y

Edited to add that the above video is not of this year's models. Still, it could be useful for you to see ereaders of various sizes lined up together for comparison.
Easy mental comparison: 6" screen == mass market paperback page, 8" screen == trade paperback or small hardcover book. If you want to read full page-sized PDFs (like academic journals or papers), you'll need something bigger than that.

I'm very happy with my Inkpad 3 (7.8" screen). I had a 6" Kindle for years before that and I sometimes still read on my older device, but the Inkpad screen is far superior. I do use the frontlight and a battery charge lasts for weeks on it.
Yes, 6 inches versus 8 inches is a big deal. Especially as you get older and your eyes get more fussy and cranky with small text.
In my case 8" 300 dpi eink screen of Kobo Aura One (using Koreader app) is usually good enough even for reading full page-sized PDF (A4 or US-letter sized academic journals), because I don't mind reading two or three screens per pdf page (in landscape mode with margins completely cropped for A4 documents with 15-16 cm text width), or four screens per page (for two-column A4 pdf in portraite, using two-column mode, or zoom & panning for three or more column pdfs), or using pdf reflow mode (e.g. for single-column A4 documents with 17-18 cm text width) when the original text width is larger than approx. 16 cm (6.2 inch) screen width of 8" reader in landscape.

If our reader and its apps are good & fast enough we could also use zoom & panning instead of its multi-column modes, fit-to-content-width landscape mode, reflow modes etc.

Also, if there are a lot of colored tables, graphs, diagrams etc. then we should use our tablet as auxiliary device, if we still wanted to read the rest of pdf document on eink screen.
This thread is so general and timeless that I have decided to stick it at the top for new visitors of MobileRead looking for information. If you want to add more comments keep them as timeless and instructional as possible for a brand new potential user with no experience.

Dale
One very important thing to consider is where you be get your ebooks. If you are going to buy them from a Store (e.g. Kobo, Amazon, Apple, ...) then you need to pair your store choice/options with the reader choice, taking into consideration the format of the ebook (ePub, AZW3, Mobi, PDF, ...) and a particular reader's ability to read various formats.
Here's a picture of the newest Paperwhite with a 6" screen on the left, the 2018 Oasis with the 7" screen on the right.

Font size at 5, thinnest line spacing and margin, screen light all the way up.

I love my Oasis, but it has a dismal battery life. I get 15-17 hours of useful life. I usually use the font size shown here, light all the way up, except when reading in a dark room. I read fast, so lots of page turns. I don't mind the poor battery enough to get rid of the Oasis, most of my reading is done at home, so charging it every 3 days isn't a problem.

I bought the Paperwhite for traveling, since it is smaller, and has a much better battery life. I haven't used it enough to know exactly yet though. It will be easier to toss in my purse for reading in the car on our upcoming trip.

Having picture uploading trouble...not sure what is wrong. I can't upload a picture from my ipad or from my computer. After I select Upload, I get a blank browser window on both.
Due to the sticky...

Apprentice Alf and Calibre should also be Googled.