So, you are in charge of making this auction happen. You got the Software, but that's only part of the story. Let's work together on a timeline/to-do list - all the steps won't apply to everyone, but let's share our experience to help the newer folks realize it doesn't have to be overwhelming, and it can even be lots of fun.

If you want to contribute, but I didn't invite you (yet), just ask and I'd be happy to do that.

When What How
Right after last auction Pick a date/venue for next year Get it on the church calendar for the entire day (allow time for setup)
Right after last auction Send out volunteer thank yous Keep those volunteers happy and feeling appreciated - they are the lifeblood of the auction
Right after last auction Send out mass email thank yous to participants Keep it brief, but it's a nice touch. Tell them how much was raised and next year's date.
Right after last auction Decide who will be in charge next year You've been working on this all year, right? It's a trade-off between continuity and burnout risk - it gets easier but you don't want to hog the spotlight either, right?
Right after last auction Host a party for the core group and pick a theme for next year This is a treat - Talk about what went well and what can be improved next time. Get a feel for who will be along for the ride next year.
4 months out First Kickoff Committee Meeting Time to start planning all the long-range stuff. Venue, decorating themes and who is going to do what centerpieces, wall decorations...etc. Make sure the auctioneer is on board. Setup a meeting schedule and publish it in the newsletter, with first call for volunteers. Update the auction page on your main website (include a link to your TogetherAuction site)
4 months out Setup the Software If this is the first time using it, read up and start practicing with it. Get the member database imported. Decide how you will 'run things' - either as we do with bidding paddles assigned at check in, or with pre-assigned paddle numbers assigned from a paper report. Decide where computers will be for sale entry, check-in, check-out. Decide if you will be tracking payments at check-out, or bulk-printing statements to hand out after sale entry. Go thru all the steps and train yourself first, then you can decide how much time it will take to train others. Call Jim if you need to - like you, he's more mellow when the auction is still a long way off ;) .
2 months out Setup your TogetherAuction home page You can edit the Notices I've started you out with, and customize the look of the main page to fit your theme. Mention the basics like date, time, ticket prices, childcare...etc. Tell when they can expect the printed catalog/addendum if you can. Use the days-ahead feature to enable/disable different 'flavors' of your messages to fit the changing urgency as the auction draws near - you can set all this up in advance instead of waiting till the last minute when you'll have other tasks to do.
1 month out Solicit donations Use the mass email feature to ask for donations. Be sure to include a direct link to each member's statement (see the sample emails I've given you) - this makes self-serve donation entry pretty painless. Put notices in the newsletter. Staff a table after church every week. Have a mailbox where folks can leave their donation forms. If you are doing a potluck, have the sign-up sheet ready and someone in charge. Have a mail list that goes to everyone on your committee so that folks can ask questions or send in photos to attach to their items.
1 month out Poster Have someone make a nice poster to advertise the event
1 month out Start proofreading Keep on top of it as new items come in rather than waiting till the end or else it won't get done very well. Often folks need to be called to supply missing info. Don't use the item notes for anything time critical - it's not email; nobody will see it unless they happen to look.
2 weeks out Meet and pick live items Your Auctioneer will likely want to be involved. Enter the list of item numbers in the auction setup page.
2 weeks out Catalog Dry Run Do the printed catalog; everything but dropping in some decorative images to fill whitespace.
2 weeks out Finalize 'stuff' Make sure music is all set, volunteer are confirmed for kitchen, cleanup, silent monitors, computer sales entry, check in, drink sales, bakesale, ...etc.
2 weeks out Make a Live PowerPoint Make a Slide show to project during the live auction
2 weeks out Get colored paper for bid sheets
a few days ahead Setup computers If borrowed, get them days or weeks ahead of time, at least for the first time (day of is too late). This gives you time to practice and hold volunteer training using the actual setup. You need to setup and test network and printers. Run a virus scanner on any computer you get before you connect it to the others. Test the ability to print signs and such.
Friday Night Before Print all the bid sheets Use different colored paper for each category.
Morning of Setup tables Lay out the silent auction bid sheets
Morning of Decorate Set up tables for dinner
Morning of Get Cashboxes Make sure each station that collects $ has a cashbox with initial $ for change. Make sure phone line for visa machine works. Make sure printers have paper and toner.
Doors Open Take Tickets Members pay for dinner - (upsell) options to buy carnations, raffle tickets, show/present a live item...etc.
Doors Open Register Get a bidding paddle, pick up a printed catalog/addendum with live item list and item event calendar
After Silent Enter Sales Collect bid sheets and start entering sales
After Silent Prep for handout Consolidate sold items to pass out
After Sales Entered Print Statements If not doing payment tracking
During Live Enter Live Sales And re-print winner statements if not doing payment tracking
After Live Check Out Collect paddles. Read total. Enter payments and print statements on demand. Collect $ during print. Winners take statements to collect loot.
After Clean up Run cash reconcile report and include with counts of each cashbox to treasurer - arrange to make bank deposit that evening.
Sundays After for 3 wks+ Cleanup Sales Have a workstation, printer, and cashbox setup after service to check out anyone that had to leave early. Also display unsold items and lay-out/tape up bid sheets with remaining seats at events for post-auction sales.

Lather, rinse, and repeat next year!

Another idea: make table fliers for items that are services or don't have anything to look at and put them out along with the bid sheets.