Your question is very broad. If you can be a bit more specific about, what you really want to know, you can get better answers. As for bankroll management I will spend up to 1% of my bankroll on an individual MTT. Right now I have 2.500$ set aside for poker, so I am allowed to play up to 22$ MTTs. I still play many, that are cheaper than that though, so on average I only spend around 0,5% of my bankroll on an MTT.
An MTT session for me typically last 5-10 hours depending on, if I make some deep runs or get tired. I have up to 4 tables running at the same time, from time to time even 5. But if I get near a final table, I prefer to let it drop to 2 or 3. Depending how it goes, the session might then contain 5-10 or sometimes more MTTs. The one, I just finished on
888 Poker, contained 8 MTTs, of which I cashed in 2 and reached a single final table, where I went out as one of the first.
If you are new to
online poker or playing purely for fun, I recommend having only 1-2 tables running, so you can fully focus on the action and finding all the good spots. But if you play for profit, it is important to eventually learn to multitable, and 4-5 tables is certainly not the ceiling for someone using a 2 monitor setup and a desk. For me though I prefer a more laid back style, so I just play on my laptop. And then 4 tables is kind of the maximum for me, unless I stack the tables, which result in a lot of missed information and autopiloting.