a) Is using the comand "setgenerate true -1" equal to pressing the start mining button OR do you first need to enter the command and then press the start mining button
Solomining OR Poolmining
Threads: 1 (default)
Scantime: 1 (default)
Debug logging: on/off (default = off)
Server: (default=empty)
Port: (default = empty)
Username: (default = empty)
Password: (default = empty)
To pool-mine, you should set the server, port, user and password fields.
c) if you want to solomine do you need to do ANYTHING else? Do you need an additional mining program? Do you need to change some settings somewhere? and so on...
However, if you are mining coins that can be mined on a GPU, you would probably miss out on 99% of the hashing power of your machine. (asuming you own an ATI graphics card)
This is also the one big reason why there is no mining function in Bitcoin-QT anymore. CPU mining is way too slow and energy-inefficient compared to GPU, FPGA and ASIC mining. Integrating GPU mining would be a way around this, but on the other hand, it also increases variables (worksize settings, vector, etc) and relies heavilly on the user's ability to install good drivers (to enable OpenCL or Cuda) wich would make the client appeal less to newcomers.
d) What do you need to do if you want to poolmine?
Ofcourse, you need to join a pool beforehand. They will provide you with a server and port adress. Username is usually your login name for the pool and a 'worker' name (has to be set at the pool) combined, separated by a dot.
Some additional info:
If you do not have the hardware to produce at least a couple 10's of Gigahashes per second, don't even think about solo mining.
Solo mining relies on you finding a block, wich will pay out 25BTC (reward used to be 50, and will devide by 2 every certain amount of coins that are mined). However, on hardware that isn't fast enough, you need to be lucky enough to find a block before anyone else does. You're boxing against 300Terahash per second (currently, constantly grows), and the odds of you finding a block before anyone else are less than a winning with a lottery ticket.
So the advice is: join a pool, install a good mining client (CGMiner, BGFminer, Bitminter if you want something extremely easy to set up) and have the latest drivers for your GPU installed. This guarantees that you get some BTC. Far less than finding a block, but guaranteed income.