I would suggest one of the hotels on Harbor. The Candy Cane Inn gets the highest reviews, has a shuttle to drop you off near the gates (and is about a 10-15 minute walk if you prefer). It also has a free continental breakfast. I have not stayed there yet but never see a bad review. I can also recommend the Howard Johnson's, the Tropicana, and the Camelot, all of which I have stayed at. Tropicana was my favorite, not fancy but super clean room, nice pool with plenty of chairs and towels and a very large hottub. Best of all, it was less than a five minute walk to the turnstiles of either
Disneyland or DCA. The closest motel to DL is the Best Western Park Place Inn (I am tryig that one in June based on the good reviews I have heard on the dis). There are many others, I would maybe go on Expedia.com and check out that website. Even if you choose to book yourself, they will have a listing of all the motels near Disneyland with photos, rates and reviews all on one site for your to check out. After you narrow down your choices, you can post them here on the dis or go to
www.tripadvisor.com It has hundreds of reviews from normal, non paid people who give their honest opinions.
I would really try to do two days at least. Disneyland and DCA are not really one day parks and mid June can be a bit crowded. Make sure you go early, get in line 30 minutes before opening since mornings are the best. Then you can take a midday break at your hotel and then go back later in the day for dinner and fireworks and more rides.
I would also make your plans very soon, mid June is just a bit over two months away and the motels near Disneyland tend to sell out or at least raise their rates as their occupancy levels go up.