I'm a Mac owner.
You'll be getting a GMail account, if you don't have one, go ahead and get one.
GMail is to Android as MobileMe is to iPhone/Mac.
First, you want to put your all of your contacts into Address Book. Next, select all contacts and then File -> Export... to a vCard.vcf file - all of contacts will be in that one file.
Log into GMail via your Mac on Safari. Select Contacts link. Follow your nose to the Import link - select by file and it lets you browse to your local machine. Specify the vCard.vcf file.
Your done syncing contacts. And ALL group relationships are preserved. Don't worry about contacts with just email and no phone numbers, you can filter for that once you have your Evo.
Do that first.
If you're running Snow Leopard, open Address Book-> Preferences -> Accounts -> Account Information and turn on Synchronize with Google. The Configure... button lets you input gmail username and password. From that point on, new contacts in your Address Book can sync with Google and vice versa.
If you don't have Snow Leopard, all of the free auto-syncing stuff sux. Using back and forth on vCard exchanges between the two by hand maybe once a month and then tell both sides to remove duplicates. Supposedly built-in Google sync works in Leopard, but that really depends on the history of the machine - so if Tiger's been there before - not really gonna happen, but you can try it.
Next - open Calendar tab on GMail. Goto settings and set your timezone and give the Calendar a name.
If you're on Snow Leopard, pop open iCal-> Preferences -> Accounts. Follow the wizard and add an account - don't go automatic, use the drop down and go WebDav for Google.
Anything in your iCal will then automagically sync with Google Calendar.
If you don't have Snow Leopard, follow the Google Calendar settings page and find the little button that says ICS under the private entry, second up from the bottom. Use that link in iCal-> File -> Import to get read-only access to your Google Calendar.
(The message here is that you want Snow Leopard.)
From the moment you turn on your Evo and enter your GMail address - your contacts and calendars are automagically sync'd with the Google web. (And all vice versa down to your Mac if you're on Snow Leopard - enter stuff on your Evo and it'll be on your Mac.) That's it, you're done!
For syncing iTunes, people have tried various things, including doubletwist. You're on a Mac. Maybe try TuneSync - Lite version is free, limits you to 20 songs in your play list to see if that's right for you, then you can buy buy the full version for $5. Others like doubletwist, and sometimes the whole iTunes syncing thing becomes a holy war.
This next week in Europe, HTC is rolling iTunes syncing support for one of their phones with the upcoming Android 2.2 update. No idea if that's coming to our US version. I think not because they'd have mentioned a feature that big in the press leaks we've all been following for the past few days.
My suggestion is to not be dissuaded by anything you see on syncing woes right off. It seems to be an improving situation.
Find TuneSync here -
How to set up wireless iTunes sync with the HTC EVO 4G - Know Your Cell
Doubletwist here -
doubleTwist Player by doubleTwist Corp - doubleTwist Android Market
Syncing by hand and a USB cable is a snap if you want to transfer albums - for playlists, it's not hard - but it's too much work for a human. You have to create the playlist name by hand, then copy/paste by hand.
So, try one of the syncing routines if you like playlists.
The stock music player in 2.1 - not so great. I've no clue what it'll be like in 2.2 being released next week.
I swear by a free app called Meridian. It will play ALL of your music files. Don't expect to get embedded art (if you've done that) from inside your ALAC (lossless) files if you have any - nor to be able to edit MP3 tags. Those are MP4 files, and nothing's broken that's going to be fixed. Meridian's appearance is not great, not polished. But - the overall app is quite good and it's like a one-stop shop for your vids and music.
People that don't prefer Meridian prefer Rockplayer, also free.
None of the decent music players include an EQ feature.
For audio quality, the Evo is __identical__ to a gen 2/gen 3 iPod Nano, if you can relate to that. So, you'll hear some audiophile griping, but it's really pretty OK as far as I'm concerned.
For an SMS app, you want Handcent SMS. Closest thing to what you're used to and highly preferred by lots of Android users. Others swear by ChompSMS - I use Handcent.
Both are free in the Market.
For voice recognition dialing, the stock app sux. You want Edwin, also free in the Market.
And you want Google Gesture Search, especially if you contact list is large. Do NOT confuse it with gesture-anything in the iPhone world. It's superior, it's fabulous and if you've got a large contact list - you'll be addicted to it in about 5 seconds.
BTW - Bluetooth File Exchange under Applications->Utilities works like a charm with the Evo. Windows users get screwed on Bluetooth software, they always have, I don't know why. So don't pay attention to BT file transfer woes if you hear of any. You can also get great service out of various free file managers that let you transfer by wifi or BT and you can initiate that from the Evo side with those.
If you're using that iPhone thing to remotely control any of your Macs - forget it. I use my Evo with a program called Remote Droid to control my Mac mini HTPC - gives you a wireless two-button trackpad and soft keyboard that can't be beat for that sort of thing - also free. In addition, you'll find a few (free) Front-Row type remote controllers that you can use between your Evo and your Mac and they're cool too - you'll have to choose if you'd like more than Remote Droid.
Then there's a free app for your Mac called calibre that will let you turn various files into eBooks. I think it's kinda raw and sucky but it does work.
That takes care of everything but the Rotary Dialer - if you recall the first iPhone keynote address - well - you can actually hose around with an on-screen rotary dialer, it works and it's a crack up.
Leave your iPhone behind, welcome to Sprint, welcome to Android, welcome to the Evo, welcome to this corner of the forums, post back if you need any specific advice on stuff.