I am concerned about the amount of record-keeping that might be necessary to prepare my tax return. Any tips on this?

We cannot advise on individual tax matters, but we have put together the following general information and a list of references that you may find helpful.
 
The IRS recognizes that day traders have a special situation, with typically dozens, or even thousands of trades a month using some systems. You can therefore do one or all of the following:
 
File for Trader Status, which provides many advantages,
Use Mark-to-Market accounting, which provides more benefits, and finally,
Establish a trading business, which provides perhaps the most advantages of all.
 
If you elect to file with Trader Status, and Mark-to-Market accounting, there are several general advantages and disadvantages summarized here:
 
The Wash Sale Rule does not apply!
No $3,000/year limit on deductibility of trading losses.
No 2% threshold for deductible investment expenses.
No limit on investment interest deductibility. (Margin interest fully deductible.)
No self-employment tax.
Unrealized Gains and Losses held at year end must be counted.
Old Capital Loss Carryforwards may be trapped on Schedule D.
 
For a summary of the rules on Trader Status, see:
 
The actual rules are page 73 ("Special Rules for Traders in Securities") of IRS Publication 550: http://www.irs.gov/pub/irs-pdf/p550.pdf 
 
NOTE: To elect Mark-to-Market accounting for 2012, you must file a statement to that effect with your 2011 taxes or with your extension request by April 15, 2012.
 

You may also want to form an entity, or a business, through which you will do your trading. There are many advantages to this. See: