Which is best for a noob?

[sneuhaus1]

49 or 61?

Why?

[MajorFubar]

Welcome.
There's no difference other than the number of keys, and ergo, the size and weight.
The number of keys you need, and the size and weight you can accommodate, is going to be a personal preference that none of us here can answer.

[Sweyn]

If it helps, I chose the 61 because it wasn't that much longer of a keyboard on my desk compared to the 49. Mainly because the two wheels are placed at the top on the 61 rather that on the side.

[jkipcount]

I'm a guitar player that's still very much a noob when it comes to playing keys, but I've always used 61 key keyboards and controllers, and I'd never go down any smaller. 

Even with my relatively simple synth playing, I can get a really low octave going and a higher lead part going together.  With a 49, I'd be limited to the higher of the two notes in the low octave pair if that makes sense, losing all that girth and grind you get from the low notes.  Or I'd have to play the lead part an octave lower, which is often not what you want if you want the excitement of that higher octave.

I honestly feel like 49 key controllers are really not compact in any way, so might as well move on up to 61. 61 is the sweet spot, even for a noob.

[Bristol_Fashion]

I'm a compromise sort of person so I've gone with 61 - big enough to feel like a full keyboard, but at the same time, compact and light, not much more expensive than the 49 but much nicer to use if you're going to be playing melodies and keyboard parts, rather than simply triggering sounds.