Here is a 2 minute primer for you.
Which camera works better in low light?
Remember these quick rules for low light shooting. It is the sensor size and sensor technology that determines the performance of camera in low light.
* Bigger the sensor, the better the camera works in low light.
* Newer the sensor, usually the camera works better in low light. An APS-C sized sensor of Canon XS or XTi does not work as good as same sized sensor in Canon 650D or T5i. Canon XS photos with ISO800 may not be usable but T5i photos with ISO 3200 may be totally usable!
* For the same sensor size, the lower the mega pixels of camera, the better it is for low light shooting. Sounds stupid, right? However if you put too many mega pixels on the same sized sensor, the sensitivity of the sensor suffers and so does its low light performance. This is because each pixel becoming smaller and hence losing some quality with respect to light sensitivity. (Read this article about what is optimum MP that I should use on my camera.)
It is not the Camera body; it is the lens that does wonders in low light
Last but not the least, most kit lenses are very very slow. Most kit lens are F3.5 which are not that great when it comes to take in light. If you want to have better low light performance, you can buy fast 1.4 or 1.8 lens and your ability to shoot in low light will go up exponentially. What an F1.8 lens can achieve in low light compared to a F3.5 kit lens, spending even $1000 more on camera body can not do! If you are going to stick to kit lens only, your best bets are Canon EOS-M that comes with 22mm F2 lens or Pentax K-01 which comes with 40mm F2.8 lenses. I have both of them (and had some other regular DSLRs too) and I can say that they take much better photos in low light than T4i or D7000. Both of these camera bodies have top tier sensor size, technology and image quality. Now 700D (t5i) does have a good lens but it will cost 2-3 times more than the two cameras I have listed above. With the money saved, I would buy a fast 35 or 50mm F1.4 lens and most people would wow at your low light photos.
Your might like to read about my favorite DSLR value buy these days (2013)
Now if you are taking low light photos, see what you are shooting. If you are shooting people or pets, even a tripod will not help you. Most of us move quick enough and will produce a blurry image. Now if you are taking photos of still objects, a tripod can come very handy. There is no simple set up for this but I would keep ISO to 100 (unless you are taking photos of plants where leaves can move or you are shooting the Moon of any even slow moving object), and f at 8-11 in Av mode. Or f at 2 to 5 if you need faster shutter speed and narrower depth of field. Will write more about this later some time but till then, please remember that it is not the camera that takes better photos; it is you who can take better photos with most cameras in most situations by becoming more pro-active.
Enjoy digital photography.
In last one decade more animals in the zoo are shot with digital cameras then the animals shot together over last 1000 years LOL. Once you buy a camera, it doesn't cost much to keep shooting.