For a new mac user following finder shortcuts will be handy.

1
Command-A
Select All Items

2
Command-C
Copy Selected Items

3
Command-D
Duplicate Selected Items

4
Command-F
Search with Spotlight

5
Command-G
Find Next Matched Search

6
Command-H
Hide Window

7
Command-I
Open Get Info (Property) Pane

8
Command-J
Show View Options

9
Command-K
Connect to Server

10
Command-L
Make Alias of Selected Items

11
Command-M
Minimize Window

12
Command-N
Open New Window

13
Command-O
Open Selected Items

14
Command-T
Copy Items to Sidebar

15
Command-V
Paste Items

16
Command-W
Close Finder Window

17
Command-Z
Undo Action

18
Command-1
View as Icons

19
Command-2
View as Lists

20
Command-3
View as Columns

21
Command-4
View as Coverflow

22
Command-Shift-A
Go to Application Folder

23
Command-Shift-B
Open Bluetooth

24
Command-Shift-C
Go to My Computer

25
Command-Shift-G
Open Address Bar

26
Command-Shift-H
Go to Home Folder

27
Command-Shift-I
Connect to iDisk

28
Command-Shift-J
Open Journler (If Any)

29
Command-Shift-K
Go to Network Folder

30
Command-Shift-L
Go to Safari

31
Command-Shift-N
Create New Folder

32
Command-Shift-Q
Log Out

33
Command-Shift-U
Go to Utility Folder

34
Command-Shift-Y
Attach to Stickies

35
Command-Option-D
Hide the Dock

36
Command-Option-M
Minimize All Windows

37
Command-Option-O
Open File and Close Finder

38
Command-Option-T
Hide Toolbar

39
Command-Option-W
Close All Windows

40
Command-R
Show Original (From Alias)