second hard drive

I have a dimension 8400.The first hard drive has windows xp on it .The 2nd hard drive has nothing yet ,but is formatted to to ntfs in the first partition and fat 32 in the second partition.

i am planning to install windows 7 on the first partition and open suse 11 on the second partition.

my question is : how to boot to this hard drive in order to start installing those operating systems? do i need to unplug my first hard drive in respect to boot to the 2nd hard drive and then pursue the instalation or there is any other way?.

The next question is after installation is done ,can i make my computer to boot to the first hard drive this time and boot to the 2nd next time ,or is there any graphical interface that i can choose where i like to boot (BETWEEN 1st and 2nd ) when i start up the computer. like when you have two operating systems on one single hard drive and at the start up you have the option to click on any of them to boot to that o/s.

And the final question is ,if that process is possible ,how do i do that .

please ,explain it with non geek language and please in the form of step by step.

Thank you all for paying attention to this matter.

soori