Some advice:

If you haven't already, buy the apple care for your machine - It's the best $180 of sanity you can buy. Applecare extends your 90 day coverage to three years - beyond the hardware coverage it includes excellent telephone support for converts, newbies, and hardcore geeks.

The first time you power on the machine, you'll be asked to create an account. By default this is an administrator account - so use an atypical name like a pet's and a good password. Only use this account to install software and run system updates. Resist the temptation to do anything in an administration account like web surfing, itunes, etc

When you create an account you're asked for a Long and Short name - the latter is very difficult to change so choose them wisely.

Since it's your first mac, you should consider re-installing right off the bat just for the experience. Would really suck needing to pop your OS install cherry the evening before a deadline but after Applecare support hours ended. It's also a good time to pare down the install by a few gigs ( that little customize button on the lower left of the final install screen ) - Leave the foreign fonts in, but do you really need all the language translation packs and print drivers etc?

Enable the software firewall, turn off the airport and/or bluetooth if you're not using them regularly

To keep yourself sane, separate work stuff from personal/leisure stuff - create regular accounts for each person using the computer for leisure and additional 'work' accounts for each person that needs one. Above all, create a separate account for your finances and filevault it.

Enable fast user switching to have multiple logged in accounts at once - just understand all the disks are visible to everyone etc

Spotlight is a pain is a pain in the a$$. Near useless as best I can tell, but does a good job of sucking up disk i/o by constantly searching for new files and generating content indexes etc. I'd suggest disabling it and sacking all the indexes it has created. read the man page first but 'mdutil -a -i off' and 'mdutil -a -E' is what you want ( yes, terminal app will be your friend )

Just like your PC, set a hot corner to start your screen saver and enable password on wake in the security panel. Never leave your screen unlocked – especially an account with admin privileges. You'd be surprised what a cat/child/roommate/lover can accomplish while you're taking a leak.

As for fat32/ntfs/hfs+… journaled HFS+ is a good choice for your external drives ( i'd leave the journal off on disks used for video editing ). You're asking for a world of hurt if you select a Case-sensitive HFS+ format it's a legacy mac thing that still fouls up some of older OS X apps

You can un-mount a disk ( internal, external, flash drive ) by dragging it to the trash and it won't delete the disk either

Every month or two you should run disk first aid on ALL your HFS disks - it's important so put it on the calendar and do it regularly. If you accidentally disconnect a disk in use, lose power, etc - connect the disk(s) and run it then and there.

disk first aid will correct most issues before things get too out of hand. open disk utility ( /Applications/Utilities ), select your disk volume, click the disk first aid tab, click verify disk.

virtual memory is nice, but slow especially if its on the same disk you're doing all your work on. 4G of ram should be plenty for most multitaskers, but if things appear sluggish you should take a look @ activity monitor ( /Applications/Utilities ) before instinctively upping the memory.

If disk i/o is your problem, move your photoshop scratch space to another disk instead of the internal disk.

If memory is really the problem - adding a 4GB kit to you mac will run ~ $120. If you need more, the price of 8GB kits are ~ $360 - in this case you'd probably be much better off procuring a 4GB ram kit, a nice sata FW800 enclosure ( < $120 ), and a cheap OCZ 30GB SSD ( $100 ). use the SSD for swap and Photoshop scratch space - no need to buy the high end SSDs as even the cheapest SSDs will max out the Firewire capabilities. ( yes, real world FW800 is much faster than USB 2 on the mac )


backups:

Time machine is pretty damn nice, but its also fairly dumb. If someone starts editing video in their account, and you didn't explicitly exclude those particular directories/disks, your time machine free space will shrink quickly… I'd suggest keeping large files off your internal drive if at all possible and limit Time machine to the internal drive only.

If you move a files around, Time machine considers them new files. Simple reorganizations will consume more backup time and disk space.

Time machine does not verify backups - you need to spot check files ( content, permissions, attributes, and ACLS ). hard disks are consumables - they have intermittent failures as do usb cables, memory, bridge boards.

Time machine slows down considerably as the number of files increases - You should consider storing your 100k RAW files on an external disk and manual backing them up to a separate disk.

Time machine is one basket - It has to be larger than the sum of all the eggs/drives/data you intend to back up. Because of this limit, I use time machine for my internal disk only. I keep all my big files on external usb drives and manually backup them up to a white box fileserver using rsync.

Time machine doesn't handle multiple destinations elegantly - you need to manually switch the destination drive in the preference panel instead of it auto-detecting disk A is connected vs disk B. You do plan on rotating between at least two backup disks right?

Keep the clutter off the Time Machine disks. The only other files I place on the Time Machine drives are compressed disk images of my installers and a simple text file with my serial numbers. Use disk utility ( /Applications/Utilities ) to create images of cd/dvds



software:

Disk Warrior and data rescue are pretty much the go to tools when things go titsup on a disk. if disk first aid fails, these will more than likely fix the problem short of a bad block on the disk.

Data Guardian is an encrypted password wallet that works rather well on OS X - helps generate 'secure' passwords ( wish it would do the same for usernames )

Thunderbird is an excellent alternative to apple iMail

stuffit expander - pretty much a requirement with macs and the internet

internet life is good with Safari, but install Opera and Firefox anyway - after you install the latter two freebies open safari prefs and pick which of the three you want as the default. Many of the IE only sites ( like online banking ) will work well with Opera.

unfortunately, Flash on the mac stores cookies by user regardless of browser - so this is another reason to have separate user account for your finance stuff

Virtualbox is great, give it a shot before Parallels etc - the virtual disks are huge and change often. Consider excluding them from time machine backup and backing them up manually. If you want to share the virtual disks between users, save them somewhere in /Users/Shared/…

littlesnitch is also a nice too but has to be set up per user account - I don't like programs dialing home with who knows what information or usage stats.

Filebuddy rocks - finding files ( especially duplicates ) is a snap

Synchronize Pro X has a nice gui, but the command line version of rsync works just as well and it's included in OSX.

GraphicConverter is the Swiss army knife of image 'can openers' - before you open jpegs with it be sure to change the thumbnails options to temporary or else it will automatically generate and re-save the file with an embedded thumbnail.

VLC is the Swiss army knife of video players…

Adium is a better than apple iChat but lacks video/audio support

Chicken of the VNC is a free VNC client if you need one