My wife and I own a Partnership LLC. In 2004 I completed IRS Schedule
E, Form 1065, and Schedule K-1 with my income and deductions.  I did
NOT include my home office expenses or depreciation in 2004.  Now for
2005, I plan to complete the same forms and include my home office
expenses and deductions.  15.4% of my home is used for my office.  My
questions are:
1. Where do I enter my home expenses?
2. Where do I enter my home depreciation?
3. Does it make sense to do an Amended Return with home expenses and
depreciation for 2004?
Any other suggestions are welcome.
Thanks

As always, see the disclaimer...this is general information, not
professional tax advice.

Since your role in the business is partner (as opposed to Sole
Proprietor with Sched. C), use the worksheet on page 24 of Publication
587, "Business Use of Your Home":
http://www.irs.gov/pub/irs-pdf/p587.pdf

This worksheet includes a section (lines 33-38) which covers
Depreciation of Your Home.

A discussion of where to take the deduction is at the bottom of the
first column, top of the second column of page 19.

Whether it makes sense to go back and make an amended return depends
on a few factors:

1) How much extra 2004 money would you get back if you added on this
deduction?  A quick way to estimate this is by multiplying the amount
of additional deduction (assuming you're not in the phase-out income
range) by your marginal tax rate (found on page 82 of the Form 1040
instructions, if you don't already know it).  For example, if your
home expenses deduction for 2005 is $1000, and that number would be
about the same for 2004, and you're in the 25% bracket, then the
additional amount you'd get back would be in the neighborhood of $250.

2) How much time would it take you to prepare the amended return(s)? 
What is the value of that time?  Alternately, if you use a
professional preparer, how much would that cost?
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Incidentally, for business owners who use Schedule C, there is a
separate form for this purpose, for 8829 "Expenses for Business Use of
Your Home":
Instructions: http://www.irs.gov/pub/irs-pdf/i8829.pdf
Form: http://www.irs.gov/pub/irs-pdf/f8829.pdf

Thanks