Why are my pictures coming up small?

(THIS IS ON ASTROPHOT0GRAPHY)
Hi there, i was taking a picture of Jupiter through my Meade LX200GPS 12". I was please with the picture but when i compared it to other pictures on Google (taken with other LX200GPS 12"s Jupiter was 10 times bigger. I take about 30 second exposures and on ISO 800. If someone could please recommend a good camera setting for Nikon D3100 taking pictures. And also why are my pictures small and how can i make them bigger.

Nikon D3100 Retouched Photos Not Showing up On Computer?

I just got a Nikon D3100 for Christmas, and I'm such a noob. I retouched a few photos using the in camera options, and then saved them on the camera. When I pull up the photos on the memory card on my computer the retouched photos are not showing up along with the rest of the photos. If I put the memory card back in the camera and view the photos on there, the retouched photos show up just fine. What in the world am I doing wrong?

Which DSLR camera shall I buy?

I'm a student currently studying a foundation degree in photography (started in september). I did photography at A-level and it is my passion. I do it as a hobby outside of uni work aswell. I'm currently on the stage of switching from bridge camera to dslr. I have used dslr cameras a lot before (nikon d3000 and d3100) but i now want to buy one of my own. Is there any that you would recommend?

And I prefer Nikon to Canon.

Video on canon camera stops recording automatically?

So normally i use a d3100 and record at 720 with no problems. But i lost my battery and had to do a video so the guy lent me his camera.

i guess its a lower end canon (Powershot SX20 IS). I don't know much about it but i got the basic down. When i tried to use the card from my nikon and record in 720 it records foor about 5 seconds and stops. It works fine at standard definition. Why would it work fine on one cam and not on the other? Do they process differently? Or id the canon detecting nikon data and getting jealous?

Also i'm using a 32GB class10 transcend card

How to set up my remote and Nikon d3100?

I just purchased this Vivitar remote for my Nikon d3100.
http://www.amazon.com/...002N6935C/
I got it today in the mail, but I'm a little confused on how to sync it to my camera. I plugged it in and turned it on, but it won't take the picture. Any ideas?

I need a speedlight for Nikon D3100?

Could you please suggest me a good speedlight for my nikon D3100 not too expensive.
And also a filter. What kind of filter do i need (polarizer, neutral density etc).
I'm just a beginner and i would really appreciate your advises

What program should I use to edit my photos?

I have PhotoFiltre and PhotoMud. I really want Photoshop but just CAN'T afford it. Any free editing stuff you'd recommend? I mostly want to enhance, sharpen, brighten, etc… I don't really like "pre-made filters", I like to control the settings…
I have a Nikon D5100. I don't like the Nikon editing software, though.

Added (1). I tried gimp about a year ago… Oh dear. It was too blah and confusing for me!

What shutter speed should i set my camera?

I have a Nikon d3000 and I recently got a 1300mm telephoto lens. What should my shutter speed be set at to get clear bright photos?

Anyone have advice for a Nikon D5000?

I bought this camera more than a year ago but i feel like i still haven't used it to it's full capabilities. I'm still learning how to use it in dark light and too bright light, and i feel like there's something i don't understand. When i want to take a night landscape or anything in low lighting how can i adjust the settings to achieve the most stable, focused photo?
does anyone have an opinion on the lens that originally comes with this camera? If there are problems is it due to the body or the lens?
and if you have experience with this camera i would be grateful for some tips, somethings i should look out for or things i should take advantage of.

Do i need to set up my warranty?

This Christmas i received a Nikon D3100 because i study Photography.

My dad told me i need to go online and set up the warranty? I'm confused by this because it already comes with 2 warranty receipts and slips, and doesn't have any information about having to go online?

Is it done and dusted or is there an online process i have to go through?