Is that good?

[LaughingJack]

Hello, I wanted to know if "24Mh/s" is good or not.

Someone told me "Mh" can be milli or mega, but I don't know how to know that.

Oh and excuse me, i'm french so I suppose I made a lot of errors. 

[Doggey]

Nah it's not good at all

You can buy something like this:
http://www.ebay.com/itm/1-Bitcoin-USB-Block-Erupter-333Mh-s-ASIC-Miner-In-Hand-and-Ready-to-Ship-/231118180119?pt=LH_DefaultDomain_0&hash=item35cfb78f17

For around $50 and it would give you 333 mh/s

M in mh/s stands for Mega as in Million

Yes Mega is one of the coolest sounding words on the planet

[Jan Doedel]

In the metric, M = mega (10⁶), while m = milli (10^-3). You can see all metric prefixes here.

If you're mining Scrypt, 24Mh/s is pretty nice. If you're mining sha-256, not so much.

[btcmonster]

nope not worth it