If you're gonna play with multiple OSes, use a boot/partition manager. I've commented in several threads that BootIt NG from http://www.terabyteunlimited.com
is the way to go. It is free to try/cheap to buy, I have used it to perform, say, 30 or installations and it goes off without a hitch every time (i.e. I have never lost data on account of it)
Sure you have the option to configure GRUB/LILO or even, say, Windows XP to manage the partitions, but I find BootIt to be easier and more flexible.
BootIt lets you have more than 4 partitions through the use of an "EMBR". You determine which 4 you want included in your partition table (chosen at boot time natively or via a very friendly user-configurable menu). When you create an EMBR, you also can create a small partition on your disk for storing the EMBR, which I highly reccomend. WARNING WARNING WARNING: any "space" not covered by a partition currently in the partition table (recall that you only get to choose 4 at any time) is seen as free space by the operating system, since "if it ain't covered in the partition table, it must be free space." DO NOT create/delete partitions outside of BootIt unless you really know what you are doing.
For Linux, I have found that the best thing to do is to create the partitions in advance and then do the install. I create one extended partition with 3 logical drives:
1) 300MB EXT2, which will be given a mount point as "/boot"
2) Another EXT2, make it whatever size you want to dedicate to Linux, this will mount as "/" (i.e. root)
3) LINUX SWAP/SOLARIS, make it twice the size of your physical RAM, to be mounted as "/swap"
You can set up your partitions, set up a configuration specifying use of the paritions, and tell the system to do a one time "BIOS sequence" boot. Stick in your Linux install CDs and tell it to roll.
On Linux install, I convert the partitions to EXT3 and specify the mount points. When I install the boot loader, I don't install it to the MBR, I install it to the hard drive designation of the "/boot" partition (i.e. /dev/sdaX where X is the designation of the /boot partition), since BootIt occupies the MBR.
You can proceed to install windows as well if you wish. Create an NTFS partition, add it to a boot configuration, and tell the system to boot the BIOS sequence, just like you did with Linux. Windows, being Windows, will overwrite the MBR, but that is OK since the BootIt EMBR is not stored in the MBR: just reinsert the BootIt CD, reboot the computer, and tell BootIt to reactivate.