tfaulkner has given you a good answer. All of those items are to be considered as "Employee Business Expenses."
With regard to your question about "per diem" rates while away - the amount and nature of your deductions depend on how long the job assignment is - 1 year or less( "Temporary"), or more than one year ("indefinite"). These situations are described on pages 186 thru 192 of IRS Publication 17, available at http://www.irs.gov/pub/irs-pdf/p17.pdf
Basically, if your job is "temporary" you tax home does not change and you can deduct travel, meals and lodging. If your job is "indefinite" your tax home changes and you have no deductions.
If your job is "temporary":
- travel expenses are deductible (Actual cost for air, taxi, train, etc. Regarding your personal car, either actual cost or $.375 per mile for 2004)
- lodging costs are deductible (Per diem does not apply, only actual cost)
- meal expenses are deductible, either actual expenses or "per diem." The per diem rate depends on where you are. Different rates apply for different locations and these rates are shown in IRS Publication 1542.
And all of these deduction amounts must be offset by any reimbursement amount received from the employer.
If this does not answer your question, please advise and I can look deeper into what you need.