I got my volvo checked by a mechanic. He gave me an estimate of what needs to be done.

How many of these items are DIY. I am a fairly good DIY person if I have instructions(replaced brakes, oil, lights, fixed a non-working window, etc)?

Where can I get the instructions for the jobs mentioned in the attachment?

 

Wow, I'd stay away from this guy...
Timing belt is easy, follow instructions available ALL OVER the place, if you screw up nothing happens if you have a noninterference motor. (Decent shop price would be $300)
Hose: a blind monkey can do that, two clamps, 10 minutes.
Valve cover: (see above) gasket is $10, 15 min. labor.
Exh. manifold: Very easy UNLESS you break a bolt/stud.
Tie rod: Easy but being suspension, could be harder, still def. DIY able.
Align: Need a "professional" for that one, should be about $40.
A/C: DIY project definitely... Do some research. Do you need it? I'd not do it unless the system is shot, and if it is shot, there may be other issues like leaks.

 

Are there any tips on how to do the valve cover? I dont know what needs to be done except that it is leaking something?
Also, what is exhaust manifold? Where can I find instructions to fix that? I have a Chilton's guide but could not find a direct section which mentions that explicitly.

 

I agree it sounds high but speaking as a DIYer and not a pro, no matter how easy it looks, it's not if but when you'll screw something up and need a pro. Your Volvo guy doesn't sound like the one. Being as it's an older 740 (read: will need on going "attention") I'd use this opportunity to go around to some other shops and see what they say you need and how much they'll charge. In my experience the relationship is just as important as the price.

 

Well, ok, you mentioned that you have done some things... Yet, your questions...
Try this:
http://www.brickboard.com/FAQ/700-900/FAQSummary1.htm